Sync

.editorconfig

@@ -1,10 +1,9 @@
-
 [*]
 
 # Microsoft .NET properties
 csharp_indent_braces = false
 csharp_new_line_before_members_in_object_initializers = false
-csharp_new_line_before_open_brace = accessors,anonymous_methods,control_blocks,events,indexers,lambdas,local_functions,methods,properties,types
+csharp_new_line_before_open_brace = accessors, anonymous_methods, control_blocks, events, indexers, lambdas, local_functions, methods, properties, types
 csharp_preferred_modifier_order = private, public, protected, internal, file, new, readonly, abstract, virtual, sealed, static, override, extern, unsafe, volatile, async, required:suggestion
 csharp_prefer_braces = true:none
 csharp_preserve_single_line_blocks = true

.idea/.idea.AdventOfCode/.idea/developer-tools.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="DeveloperToolsToolWindowSettingsV1" lastSelectedContentNodeId="base64-encoder-decoder">
+    <developerToolsConfigurations />
+  </component>
+</project>

.idea/.idea.AdventOfCode/.idea/dictionaries/var.xml

@@ -0,0 +1,3 @@
+<component name="ProjectDictionaryState">
+  <dictionary name="var" />
+</component>

AdventOfCode.Common/AdventOfCode.Common.csproj

@@ -1,10 +1,10 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
-        <RootNamespace>AdventOfCode.Common</RootNamespace>
         <Nullable>enable</Nullable>
+        <RootNamespace>AdventOfCode.Common</RootNamespace>
     </PropertyGroup>
 
 </Project>

AdventOfCode.Common/DayHelper.cs

@@ -14,8 +14,8 @@ public static class DayHelper
         }
         return null;
     }
-    
+
-    public static void RunDay(string eventName, int dayNumber)
+    private static void RunDay(string eventName, int dayNumber)
     {
         Console.WriteLine($"Day {dayNumber:00}");
         Console.WriteLine("------");
@@ -63,8 +63,8 @@ public static class DayHelper
             Console.WriteLine(ex.StackTrace);
         }
     }
-    
+
-    public static void RunDay(string eventName)
+    private static void RunDay(string eventName)
     {
         for (int currentDay = 1; currentDay < 25; currentDay++)
         {
@@ -74,7 +74,7 @@ public static class DayHelper
             Console.WriteLine(string.Empty);
         }
     }
-    
+
     public static void RunDay(string eventName, string[] args)
     {
         if (args.Length > 0)

AdventOfCode.sln

@@ -1,73 +0,0 @@
-
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 16
-VisualStudioVersion = 16.0.30711.63
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "AdventOfCode2020", "AdventOfCode2020\AdventOfCode2020.csproj", "{CD1829F6-166D-4F78-AB95-C58916F42494}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AdventOfCode2020.Tests", "AdventOfCode2020.Tests\AdventOfCode2020.Tests.csproj", "{2B079D7D-08D4-4FFB-A000-858FFDD945FA}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AdventOfCode2017", "AdventOfCode2017\AdventOfCode2017.csproj", "{49C8A67C-D94C-4CFB-B7FB-C19A1A83CA66}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AdventOfCode2017.Tests", "AdventOfCode2017.Tests\AdventOfCode2017.Tests.csproj", "{3537CE59-1C57-481B-85F7-3F2A1F0EDE1D}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AdventOfCode2018", "AdventOfCode2018\AdventOfCode2018.csproj", "{43DAF84F-369A-48C5-9292-536094336F8F}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AdventOfCode2018.Tests", "AdventOfCode2018.Tests\AdventOfCode2018.Tests.csproj", "{EE35694D-97C1-485D-9FFE-73912FA97446}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AdventOfCode2023", "AdventOfCode2023\AdventOfCode2023.csproj", "{0D90084C-D2D9-489E-BFC3-5E63AE9947B3}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AdventOfCode2023.Tests", "AdventOfCode2023.Tests\AdventOfCode2023.Tests.csproj", "{00869F26-F53E-451D-BEA2-4E3FFE2216FB}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AdventOfCode.Common", "AdventOfCode.Common\AdventOfCode.Common.csproj", "{D6C2B27F-22C3-49E2-9591-225B7132452D}"
-EndProject
-Global
-	GlobalSection(SolutionConfigurationPlatforms) = preSolution
-		Debug|Any CPU = Debug|Any CPU
-		Release|Any CPU = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{CD1829F6-166D-4F78-AB95-C58916F42494}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{CD1829F6-166D-4F78-AB95-C58916F42494}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{CD1829F6-166D-4F78-AB95-C58916F42494}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{CD1829F6-166D-4F78-AB95-C58916F42494}.Release|Any CPU.Build.0 = Release|Any CPU
-		{2B079D7D-08D4-4FFB-A000-858FFDD945FA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{2B079D7D-08D4-4FFB-A000-858FFDD945FA}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{2B079D7D-08D4-4FFB-A000-858FFDD945FA}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{2B079D7D-08D4-4FFB-A000-858FFDD945FA}.Release|Any CPU.Build.0 = Release|Any CPU
-		{49C8A67C-D94C-4CFB-B7FB-C19A1A83CA66}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{49C8A67C-D94C-4CFB-B7FB-C19A1A83CA66}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{49C8A67C-D94C-4CFB-B7FB-C19A1A83CA66}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{49C8A67C-D94C-4CFB-B7FB-C19A1A83CA66}.Release|Any CPU.Build.0 = Release|Any CPU
-		{3537CE59-1C57-481B-85F7-3F2A1F0EDE1D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{3537CE59-1C57-481B-85F7-3F2A1F0EDE1D}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{3537CE59-1C57-481B-85F7-3F2A1F0EDE1D}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{3537CE59-1C57-481B-85F7-3F2A1F0EDE1D}.Release|Any CPU.Build.0 = Release|Any CPU
-		{43DAF84F-369A-48C5-9292-536094336F8F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{43DAF84F-369A-48C5-9292-536094336F8F}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{43DAF84F-369A-48C5-9292-536094336F8F}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{43DAF84F-369A-48C5-9292-536094336F8F}.Release|Any CPU.Build.0 = Release|Any CPU
-		{EE35694D-97C1-485D-9FFE-73912FA97446}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{EE35694D-97C1-485D-9FFE-73912FA97446}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{EE35694D-97C1-485D-9FFE-73912FA97446}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{EE35694D-97C1-485D-9FFE-73912FA97446}.Release|Any CPU.Build.0 = Release|Any CPU
-		{0D90084C-D2D9-489E-BFC3-5E63AE9947B3}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{0D90084C-D2D9-489E-BFC3-5E63AE9947B3}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{0D90084C-D2D9-489E-BFC3-5E63AE9947B3}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{0D90084C-D2D9-489E-BFC3-5E63AE9947B3}.Release|Any CPU.Build.0 = Release|Any CPU
-		{00869F26-F53E-451D-BEA2-4E3FFE2216FB}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{00869F26-F53E-451D-BEA2-4E3FFE2216FB}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{00869F26-F53E-451D-BEA2-4E3FFE2216FB}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{00869F26-F53E-451D-BEA2-4E3FFE2216FB}.Release|Any CPU.Build.0 = Release|Any CPU
-		{D6C2B27F-22C3-49E2-9591-225B7132452D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{D6C2B27F-22C3-49E2-9591-225B7132452D}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{D6C2B27F-22C3-49E2-9591-225B7132452D}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{D6C2B27F-22C3-49E2-9591-225B7132452D}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
-	EndGlobalSection
-	GlobalSection(ExtensibilityGlobals) = postSolution
-		SolutionGuid = {4BAE59D7-7AFF-42B6-A391-CD22CD443B03}
-	EndGlobalSection
-EndGlobal

AdventOfCode.sln.DotSettings

@@ -6,9 +6,12 @@
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=VY/@EntryIndexedValue">VY</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=Locals/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="aaBb_AaBb" /&gt;</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=TypesAndNamespaces/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="AaBb_AaBb" /&gt;</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/UserRules/=61a991a4_002Dd0a3_002D4d19_002D90a5_002Df8f4d75c30c1/@EntryIndexedValue">&lt;Policy&gt;&lt;Descriptor Staticness="Any" AccessRightKinds="Any" Description="Local variables"&gt;&lt;ElementKinds&gt;&lt;Kind Name="LOCAL_VARIABLE" /&gt;&lt;/ElementKinds&gt;&lt;/Descriptor&gt;&lt;Policy Inspect="True" Prefix="" Suffix="" Style="aaBb_AaBb" /&gt;&lt;/Policy&gt;</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/UserRules/=a0b4bc4d_002Dd13b_002D4a37_002Db37e_002Dc9c6864e4302/@EntryIndexedValue">&lt;Policy&gt;&lt;Descriptor Staticness="Any" AccessRightKinds="Any" Description="Types and namespaces"&gt;&lt;ElementKinds&gt;&lt;Kind Name="NAMESPACE" /&gt;&lt;Kind Name="CLASS" /&gt;&lt;Kind Name="STRUCT" /&gt;&lt;Kind Name="ENUM" /&gt;&lt;Kind Name="DELEGATE" /&gt;&lt;/ElementKinds&gt;&lt;/Descriptor&gt;&lt;Policy Inspect="True" Prefix="" Suffix="" Style="AaBb_AaBb" /&gt;&lt;/Policy&gt;</s:String>
 	<s:Boolean x:Key="/Default/Environment/Filtering/ExcludeCoverageFilters/=AdventOfCode_002A_002ETests_003B_002A_003B_002A_003B_002A/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/Filtering/ExcludeCoverageFilters/=AdventOfCode_002ECommon_003B_002A_003B_002A_003B_002A/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/Filtering/ExcludeCoverageFilters/=_002A_003B_002A_003BProgram_003B_002A/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EPredefinedNamingRulesToUserRulesUpgrade/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Chrono/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Extrapolator/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=extrapolators/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>

AdventOfCode.slnx

@@ -0,0 +1,13 @@
+<Solution>
+    <Project Path="AdventOfCode.Common\AdventOfCode.Common.csproj" Type="Classic C#"/>
+    <Project Path="AdventOfCode2017.Tests\AdventOfCode2017.Tests.csproj" Type="Classic C#"/>
+    <Project Path="AdventOfCode2017\AdventOfCode2017.csproj" Type="Classic C#"/>
+    <Project Path="AdventOfCode2018.Tests\AdventOfCode2018.Tests.csproj" Type="Classic C#"/>
+    <Project Path="AdventOfCode2018\AdventOfCode2018.csproj" Type="Classic C#"/>
+    <Project Path="AdventOfCode2020.Tests\AdventOfCode2020.Tests.csproj" Type="Classic C#"/>
+    <Project Path="AdventOfCode2020\AdventOfCode2020.csproj"/>
+    <Project Path="AdventOfCode2023.Tests\AdventOfCode2023.Tests.csproj" Type="Classic C#"/>
+    <Project Path="AdventOfCode2023\AdventOfCode2023.csproj" Type="Classic C#"/>
+    <Project Path="AdventOfCode2024.Tests\AdventOfCode2024.Tests.csproj" Type="Classic C#"/>
+    <Project Path="AdventOfCode2024\AdventOfCode2024.csproj" Type="Classic C#"/>
+</Solution>

AdventOfCode2017.Tests/AdventOfCode2017.Tests.csproj

@@ -1,24 +1,26 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <PropertyGroup>
+    <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
+        <ImplicitUsings>enable</ImplicitUsings>
-    <RootNamespace>AdventOfCode2017.Tests</RootNamespace>
+        <Nullable>enable</Nullable>
-    
+        <RootNamespace>AdventOfCode2017.Tests</RootNamespace>
-    <IsPackable>false</IsPackable>
-  </PropertyGroup>
 
-  <ItemGroup>
+        <IsPackable>false</IsPackable>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+        <IsTestProject>true</IsTestProject>
-    <PackageReference Include="xunit" Version="2.6.3" />
+    </PropertyGroup>
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.5">
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-      <PrivateAssets>all</PrivateAssets>
-    </PackageReference>
-  </ItemGroup>
 
-  <ItemGroup>
+    <ItemGroup>
-    <ProjectReference Include="..\AdventOfCode2017\AdventOfCode2017.csproj" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0"/>
-  </ItemGroup>
+        <PackageReference Include="xunit" Version="2.6.3"/>
+        <PackageReference Include="xunit.runner.visualstudio" Version="2.5.5">
+            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+            <PrivateAssets>all</PrivateAssets>
+        </PackageReference>
+    </ItemGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\AdventOfCode2017\AdventOfCode2017.csproj"/>
+    </ItemGroup>
 
 </Project>

AdventOfCode2017.Tests/Day01_Tests.cs

@@ -9,7 +9,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart1(new[] { "1122", });
+        string result = day01.ResolvePart1(["1122"]);
 
         Assert.Equal("3", result);
     }
@@ -19,7 +19,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart1(new[] { "1111", });
+        string result = day01.ResolvePart1(["1111"]);
 
         Assert.Equal("4", result);
     }
@@ -29,7 +29,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart1(new[] { "1234", });
+        string result = day01.ResolvePart1(["1234"]);
 
         Assert.Equal("0", result);
     }
@@ -39,7 +39,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart1(new[] { "91212129", });
+        string result = day01.ResolvePart1(["91212129"]);
 
         Assert.Equal("9", result);
     }
@@ -47,13 +47,13 @@ public class Day01_Tests
     #endregion ResolvePart1
 
     #region ResolvePart2
-        
+
     [Fact]
     public void ResolvePart2__Test1()
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart2(new[] { "1212", });
+        string result = day01.ResolvePart2(["1212"]);
 
         Assert.Equal("6", result);
     }
@@ -63,7 +63,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart2(new[] { "1221", });
+        string result = day01.ResolvePart2(["1221"]);
 
         Assert.Equal("0", result);
     }
@@ -73,7 +73,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart2(new[] { "123425", });
+        string result = day01.ResolvePart2(["123425"]);
 
         Assert.Equal("4", result);
     }
@@ -83,7 +83,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart2(new[] { "123123", });
+        string result = day01.ResolvePart2(["123123"]);
 
         Assert.Equal("12", result);
     }
@@ -93,7 +93,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart2(new[] { "12131415", });
+        string result = day01.ResolvePart2(["12131415"]);
 
         Assert.Equal("4", result);
     }

AdventOfCode2017.Tests/Day02_Tests.cs

@@ -7,11 +7,11 @@ public class Day02_Tests
     {
         Day02 day02 = new();
 
-        string result = day02.ResolvePart1(new[] {
+        string result = day02.ResolvePart1([
             "5 1 9 5",
             "7 5 3",
             "2 4 6 8",
-        });
+        ]);
 
         Assert.Equal("18", result);
     }
@@ -21,11 +21,11 @@ public class Day02_Tests
     {
         Day02 day02 = new();
 
-        string result = day02.ResolvePart2(new[] {
+        string result = day02.ResolvePart2([
             "5 9 2 8",
             "9 4 7 3",
             "3 8 6 5",
-        });
+        ]);
 
         Assert.Equal("9", result);
     }

AdventOfCode2017.Tests/packages.config

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<packages>
-  <package id="MSTest.TestAdapter" version="1.3.2" targetFramework="net461" />
-  <package id="MSTest.TestFramework" version="1.3.2" targetFramework="net461" />
-</packages>

AdventOfCode2017/AdventOfCode2017.csproj

@@ -1,20 +1,21 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <PropertyGroup>
+    <PropertyGroup>
-    <OutputType>Exe</OutputType>
+        <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
+        <ImplicitUsings>enable</ImplicitUsings>
-    <RootNamespace>AdventOfCode2017</RootNamespace>
+        <Nullable>enable</Nullable>
-  </PropertyGroup>
+        <RootNamespace>AdventOfCode2017</RootNamespace>
+    </PropertyGroup>
 
-  <ItemGroup>
+    <ItemGroup>
-    <None Update="inputs\*">
+        <None Update="inputs\*">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+            <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </None>
+        </None>
-  </ItemGroup>
+    </ItemGroup>
 
-  <ItemGroup>
+    <ItemGroup>
-    <ProjectReference Include="..\AdventOfCode.Common\AdventOfCode.Common.csproj" />
+        <ProjectReference Include="..\AdventOfCode.Common\AdventOfCode.Common.csproj"/>
-  </ItemGroup>
+    </ItemGroup>
 
 </Project>

AdventOfCode2017/Day01.cs

@@ -48,10 +48,10 @@ public class Day01 : IDay
     {
         string input = inputs[0];
         int value = 0;
-        for(int i = 0; i < input.Length; i++)
+        for (int i = 0; i < input.Length; i++)
         {
             int nextI = (i + 1) % input.Length;
-            if(input[i] == input[nextI])
+            if (input[i] == input[nextI])
             {
                 value += (input[i] - '0');
             }

AdventOfCode2017/Day02.cs

@@ -51,10 +51,10 @@ public class Day02 : IDay
     public string ResolvePart1(string[] inputs)
     {
         int checksum = 0;
-        foreach(string input in inputs)
+        foreach (string input in inputs)
         {
             int[] row = input
-                .Split(new[] { " ", "	" }, StringSplitOptions.RemoveEmptyEntries)
+                .Split([" ", "	"], StringSplitOptions.RemoveEmptyEntries)
                 .Select(cell => Convert.ToInt32(cell))
                 .ToArray();
             int max = row.Max();
@@ -70,7 +70,7 @@ public class Day02 : IDay
         foreach (string input in inputs)
         {
             int[] row = input
-                .Split(new[] { " ", "	" }, StringSplitOptions.RemoveEmptyEntries)
+                .Split([" ", "	"], StringSplitOptions.RemoveEmptyEntries)
                 .Select(cell => Convert.ToInt32(cell))
                 .ToArray();
 

AdventOfCode2017/Day03.cs

@@ -30,11 +30,11 @@ public class Day03 : IDay
 {
     public string ResolvePart1(string[] inputs)
     {
-        return null;
+        return string.Empty;
     }
 
     public string ResolvePart2(string[] inputs)
     {
-        return null;
+        return string.Empty;
     }
 }

AdventOfCode2018.Tests/AdventOfCode2018.Tests.csproj

@@ -1,24 +1,26 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <PropertyGroup>
+    <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
+        <ImplicitUsings>enable</ImplicitUsings>
-    <RootNamespace>AdventOfCode2018.Tests</RootNamespace>
+        <Nullable>enable</Nullable>
+        <RootNamespace>AdventOfCode2018.Tests</RootNamespace>
 
-    <IsPackable>false</IsPackable>
+        <IsPackable>false</IsPackable>
-  </PropertyGroup>
+        <IsTestProject>true</IsTestProject>
+    </PropertyGroup>
 
-  <ItemGroup>
+    <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0"/>
-    <PackageReference Include="xunit" Version="2.6.3" />
+        <PackageReference Include="xunit" Version="2.6.3"/>
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.5">
+        <PackageReference Include="xunit.runner.visualstudio" Version="2.5.5">
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-      <PrivateAssets>all</PrivateAssets>
+            <PrivateAssets>all</PrivateAssets>
-    </PackageReference>
+        </PackageReference>
-  </ItemGroup>
+    </ItemGroup>
 
-  <ItemGroup>
+    <ItemGroup>
-    <ProjectReference Include="..\AdventOfCode2018\AdventOfCode2018.csproj" />
+        <ProjectReference Include="..\AdventOfCode2018\AdventOfCode2018.csproj"/>
-  </ItemGroup>
+    </ItemGroup>
 
 </Project>

AdventOfCode2018.Tests/Day01_Tests.cs

@@ -9,7 +9,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart1(new[] { "+1", "-2", "+3", "+1", });
+        string result = day01.ResolvePart1(["+1", "-2", "+3", "+1"]);
 
         Assert.Equal("3", result);
     }
@@ -19,7 +19,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart1(new[] { "+1", "+1", "+1", });
+        string result = day01.ResolvePart1(["+1", "+1", "+1"]);
 
         Assert.Equal("3", result);
     }
@@ -29,7 +29,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart1(new[] { "+1", "+1", "-2", });
+        string result = day01.ResolvePart1(["+1", "+1", "-2"]);
 
         Assert.Equal("0", result);
     }
@@ -39,7 +39,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart1(new[] { "-1", "-2", "-3", });
+        string result = day01.ResolvePart1(["-1", "-2", "-3"]);
 
         Assert.Equal("-6", result);
     }
@@ -53,7 +53,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart2(new[] { "+1", "-2", "+3", "+1", });
+        string result = day01.ResolvePart2(["+1", "-2", "+3", "+1"]);
 
         Assert.Equal("2", result);
     }
@@ -63,7 +63,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart2(new[] { "+1", "-1", });
+        string result = day01.ResolvePart2(["+1", "-1"]);
 
         Assert.Equal("0", result);
     }
@@ -73,7 +73,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart2(new[] { "+3", "+3", "+4", "-2", "-4", });
+        string result = day01.ResolvePart2(["+3", "+3", "+4", "-2", "-4"]);
 
         Assert.Equal("10", result);
     }
@@ -83,7 +83,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart2(new[] { "-6", "+3", "+8", "+5", "-6", });
+        string result = day01.ResolvePart2(["-6", "+3", "+8", "+5", "-6"]);
 
         Assert.Equal("5", result);
     }
@@ -93,7 +93,7 @@ public class Day01_Tests
     {
         Day01 day01 = new();
 
-        string result = day01.ResolvePart2(new[] { "+7", "+7", "-2", "-7", "-4", });
+        string result = day01.ResolvePart2(["+7", "+7", "-2", "-7", "-4"]);
 
         Assert.Equal("14", result);
     }

AdventOfCode2018.Tests/Day02_Tests.cs

@@ -7,7 +7,7 @@ public class Day02_Tests
     {
         Day02 day02 = new();
 
-        string result = day02.ResolvePart1(new[] {
+        string result = day02.ResolvePart1([
             "abcdef",
             "bababc",
             "abbcde",
@@ -15,7 +15,7 @@ public class Day02_Tests
             "aabcdd",
             "abcdee",
             "ababab",
-        });
+        ]);
 
         Assert.Equal("12", result);
     }
@@ -25,7 +25,7 @@ public class Day02_Tests
     {
         Day02 day02 = new();
 
-        string result = day02.ResolvePart2(new[] {
+        string result = day02.ResolvePart2([
             "abcde",
             "fghij",
             "klmno",
@@ -33,7 +33,7 @@ public class Day02_Tests
             "fguij",
             "axcye",
             "wvxyz",
-        });
+        ]);
 
         Assert.Equal("fgij", result);
     }

AdventOfCode2018.Tests/Day03_Tests.cs

@@ -90,17 +90,17 @@ public class Day03_Tests
     }
 
     #endregion Claim_Overlaps
-    
+
     [Fact]
     public void ResolvePart1__Test()
     {
         Day03 day03 = new();
 
-        string result = day03.ResolvePart1(new[] {
+        string result = day03.ResolvePart1([
             "#1 @ 1,3: 4x4",
             "#2 @ 3,1: 4x4",
             "#3 @ 5,5: 2x2",
-        });
+        ]);
 
         Assert.Equal("4", result);
     }
@@ -110,11 +110,11 @@ public class Day03_Tests
     {
         Day03 day03 = new();
 
-        string result = day03.ResolvePart2(new[] {
+        string result = day03.ResolvePart2([
             "#1 @ 1,3: 4x4",
             "#2 @ 3,1: 4x4",
             "#3 @ 5,5: 2x2",
-        });
+        ]);
 
         Assert.Equal("3", result);
     }

AdventOfCode2018.Tests/Day04_Tests.cs

@@ -50,7 +50,7 @@ public class Day04_Tests
     [Fact]
     public void GuardEvent_FromStringArray__TestBase()
     {
-        List<Day04.GuardEvent> guardEvents = Day04.GuardEvent.FromStringArray(new[] {
+        List<Day04.GuardEvent> guardEvents = Day04.GuardEvent.FromStringArray([
             "[1518-11-01 00:00] Guard #10 begins shift",
             "[1518-11-01 00:05] falls asleep",
             "[1518-11-01 00:25] wakes up",
@@ -59,7 +59,7 @@ public class Day04_Tests
             "[1518-11-01 23:58] Guard #99 begins shift",
             "[1518-11-02 00:40] falls asleep",
             "[1518-11-02 00:50] wakes up",
-        });
+        ]);
 
         Assert.Equal(10, guardEvents[0].ID);
         Assert.Equal(Day04.GuardEventType.ShiftBegin, guardEvents[0].Type);
@@ -89,7 +89,7 @@ public class Day04_Tests
     [Fact]
     public void GuardEvent_FromStringArray__TestBaseUnsorted()
     {
-        List<Day04.GuardEvent> guardEvents = Day04.GuardEvent.FromStringArray(new[] {
+        List<Day04.GuardEvent> guardEvents = Day04.GuardEvent.FromStringArray([
             "[1518-11-01 00:00] Guard #10 begins shift",
             "[1518-11-01 23:58] Guard #99 begins shift",
             "[1518-11-01 00:30] falls asleep",
@@ -98,7 +98,7 @@ public class Day04_Tests
             "[1518-11-02 00:50] wakes up",
             "[1518-11-01 00:55] wakes up",
             "[1518-11-01 00:25] wakes up",
-        });
+        ]);
 
         Assert.Equal(10, guardEvents[0].ID);
         Assert.Equal(Day04.GuardEventType.ShiftBegin, guardEvents[0].Type);
@@ -126,13 +126,13 @@ public class Day04_Tests
     }
 
     #endregion GuardEvent_FromStringArray
-    
+
     [Fact]
     public void ResolvePart1__BaseStatement()
     {
         Day04 day04 = new();
 
-        string result = day04.ResolvePart1(new[] {
+        string result = day04.ResolvePart1([
             "[1518-11-01 00:00] Guard #10 begins shift",
             "[1518-11-01 00:05] falls asleep",
             "[1518-11-01 00:25] wakes up",
@@ -150,7 +150,7 @@ public class Day04_Tests
             "[1518-11-05 00:03] Guard #99 begins shift",
             "[1518-11-05 00:45] falls asleep",
             "[1518-11-05 00:55] wakes up",
-        });
+        ]);
 
         Assert.Equal("240", result);
     }
@@ -160,7 +160,7 @@ public class Day04_Tests
     {
         Day04 day04 = new();
 
-        string result = day04.ResolvePart1(new[] {
+        string result = day04.ResolvePart1([
             "[1518-11-04 00:36] falls asleep",
             "[1518-11-04 00:46] wakes up",
             "[1518-11-05 00:03] Guard #99 begins shift",
@@ -178,7 +178,7 @@ public class Day04_Tests
             "[1518-11-01 00:55] wakes up",
             "[1518-11-01 23:58] Guard #99 begins shift",
             "[1518-11-05 00:55] wakes up",
-        });
+        ]);
 
         Assert.Equal("240", result);
     }
@@ -189,7 +189,7 @@ public class Day04_Tests
     {
         Day04 day04 = new();
 
-        string result = day04.ResolvePart2(new[] {
+        string result = day04.ResolvePart2([
             "[1518-11-01 00:00] Guard #10 begins shift",
             "[1518-11-01 00:05] falls asleep",
             "[1518-11-01 00:25] wakes up",
@@ -207,7 +207,7 @@ public class Day04_Tests
             "[1518-11-05 00:03] Guard #99 begins shift",
             "[1518-11-05 00:45] falls asleep",
             "[1518-11-05 00:55] wakes up",
-        });
+        ]);
 
         Assert.Equal("4455", result);
     }
@@ -217,7 +217,7 @@ public class Day04_Tests
     {
         Day04 day04 = new();
 
-        string result = day04.ResolvePart2(new[] {
+        string result = day04.ResolvePart2([
             "[1518-11-04 00:36] falls asleep",
             "[1518-11-04 00:46] wakes up",
             "[1518-11-05 00:03] Guard #99 begins shift",
@@ -235,7 +235,7 @@ public class Day04_Tests
             "[1518-11-01 00:55] wakes up",
             "[1518-11-01 23:58] Guard #99 begins shift",
             "[1518-11-05 00:55] wakes up",
-        });
+        ]);
 
         Assert.Equal("4455", result);
     }

AdventOfCode2018.Tests/Day05_Tests.cs

@@ -7,7 +7,7 @@ public class Day05_Tests
     {
         Day05 day05 = new();
 
-        string result = day05.ResolvePart1(new[] { "dabAcCaCBAcCcaDA" });
+        string result = day05.ResolvePart1(["dabAcCaCBAcCcaDA"]);
 
         Assert.Equal("10", result);
     }
@@ -17,7 +17,7 @@ public class Day05_Tests
     {
         Day05 day05 = new();
 
-        string result = day05.ResolvePart2(new[] { "dabAcCaCBAcCcaDA" });
+        string result = day05.ResolvePart2(["dabAcCaCBAcCcaDA"]);
 
         Assert.Equal("4", result);
     }

AdventOfCode2018.Tests/Day06_Tests.cs

@@ -7,28 +7,28 @@ public class Day06_Tests
     [Fact]
     public void ChronoPoint_FromString__Test1()
     {
-        Day06.ChronoPoint point = Day06.ChronoPoint.FromString("1, 1");
+        Day06.ChronoPoint? point = Day06.ChronoPoint.FromString("1, 1");
 
-        Assert.Equal(1, point.X);
+        Assert.Equal(1, point?.X);
-        Assert.Equal(1, point.Y);
+        Assert.Equal(1, point?.Y);
     }
 
     [Fact]
     public void ChronoPoint_FromString__Test2()
     {
-        Day06.ChronoPoint point = Day06.ChronoPoint.FromString("1, 6");
+        Day06.ChronoPoint? point = Day06.ChronoPoint.FromString("1, 6");
 
-        Assert.Equal(1, point.X);
+        Assert.Equal(1, point?.X);
-        Assert.Equal(6, point.Y);
+        Assert.Equal(6, point?.Y);
     }
 
     [Fact]
     public void ChronoPoint_FromString__Test3()
     {
-        Day06.ChronoPoint point = Day06.ChronoPoint.FromString("8, 9");
+        Day06.ChronoPoint? point = Day06.ChronoPoint.FromString("8, 9");
 
-        Assert.Equal(8, point.X);
+        Assert.Equal(8, point?.X);
-        Assert.Equal(9, point.Y);
+        Assert.Equal(9, point?.Y);
     }
 
     #endregion ChronoPoint_FromString
@@ -38,9 +38,12 @@ public class Day06_Tests
     [Fact]
     public void ChronoPoint_ManhattanDistance__Test1()
     {
-        Day06.ChronoPoint p0 = Day06.ChronoPoint.FromString("8, 9");
+        Day06.ChronoPoint? p0 = Day06.ChronoPoint.FromString("8, 9");
-        Day06.ChronoPoint p1 = Day06.ChronoPoint.FromString("1, 6");
+        Day06.ChronoPoint? p1 = Day06.ChronoPoint.FromString("1, 6");
 
+        Assert.NotNull(p0);
+        Assert.NotNull(p1);
+        
         int distance = Day06.ChronoPoint.ManhattanDistance(p0, p1);
 
         Assert.Equal(10, distance);
@@ -49,9 +52,12 @@ public class Day06_Tests
     [Fact]
     public void ChronoPoint_ManhattanDistance__Test2()
     {
-        Day06.ChronoPoint p0 = Day06.ChronoPoint.FromString("1, 1");
+        Day06.ChronoPoint? p0 = Day06.ChronoPoint.FromString("1, 1");
-        Day06.ChronoPoint p1 = Day06.ChronoPoint.FromString("1, 6");
+        Day06.ChronoPoint? p1 = Day06.ChronoPoint.FromString("1, 6");
 
+        Assert.NotNull(p0);
+        Assert.NotNull(p1);
+        
         int distance = Day06.ChronoPoint.ManhattanDistance(p0, p1);
 
         Assert.Equal(5, distance);
@@ -64,14 +70,14 @@ public class Day06_Tests
     {
         Day06 day06 = new();
 
-        string result = day06.ResolvePart1(new[] {
+        string result = day06.ResolvePart1([
             "1, 1",
             "1, 6",
             "8, 3",
             "3, 4",
             "5, 5",
             "8, 9",
-        });
+        ]);
 
         Assert.Equal("17", result);
     }
@@ -79,16 +85,16 @@ public class Day06_Tests
     [Fact]
     public void ResolvePart2__Test()
     {
-        Day06 day06 = new() { DistanceThresold = 32, };
+        Day06 day06 = new() { DistanceThreshold = 32, };
 
-        string result = day06.ResolvePart2(new[] {
+        string result = day06.ResolvePart2([
             "1, 1",
             "1, 6",
             "8, 3",
             "3, 4",
             "5, 5",
             "8, 9",
-        });
+        ]);
 
         Assert.Equal("16", result);
     }

AdventOfCode2018.Tests/Day07_Tests.cs

@@ -7,7 +7,7 @@ public class Day07_Tests
     {
         Day07 day07 = new();
 
-        string result = day07.ResolvePart1(new[] {
+        string result = day07.ResolvePart1([
             "Step C must be finished before step A can begin.",
             "Step C must be finished before step F can begin.",
             "Step A must be finished before step B can begin.",
@@ -15,7 +15,7 @@ public class Day07_Tests
             "Step B must be finished before step E can begin.",
             "Step D must be finished before step E can begin.",
             "Step F must be finished before step E can begin.",
-        });
+        ]);
 
         Assert.Equal("CABDFE", result);
     }
@@ -25,7 +25,7 @@ public class Day07_Tests
     {
         Day07 day07 = new() { BaseCost = 0, NumberOfWorkers = 2 };
 
-        string result = day07.ResolvePart2(new[] {
+        string result = day07.ResolvePart2([
             "Step C must be finished before step A can begin.",
             "Step C must be finished before step F can begin.",
             "Step A must be finished before step B can begin.",
@@ -33,7 +33,7 @@ public class Day07_Tests
             "Step B must be finished before step E can begin.",
             "Step D must be finished before step E can begin.",
             "Step F must be finished before step E can begin.",
-        });
+        ]);
 
         Assert.Equal("15", result);
     }

AdventOfCode2018.Tests/Day08_Tests.cs

@@ -28,13 +28,13 @@ public class Day08_Tests
         Assert.Single(result.Childs[1].Childs[0].Metadata);
         Assert.Equal(99, result.Childs[1].Childs[0].Metadata[0]);
     }
-    
+
     [Fact]
     public void ResolvePart1__Test()
     {
         Day08 day = new();
 
-        string result = day.ResolvePart1(new[] { "2 3 0 3 10 11 12 1 1 0 1 99 2 1 1 2", });
+        string result = day.ResolvePart1(["2 3 0 3 10 11 12 1 1 0 1 99 2 1 1 2"]);
 
         Assert.Equal("138", result);
     }
@@ -44,7 +44,7 @@ public class Day08_Tests
     {
         Day08 day = new();
 
-        string result = day.ResolvePart2(new[] { "2 3 0 3 10 11 12 1 1 0 1 99 2 1 1 2", });
+        string result = day.ResolvePart2(["2 3 0 3 10 11 12 1 1 0 1 99 2 1 1 2"]);
 
         Assert.Equal("66", result);
     }

AdventOfCode2018.Tests/Day09_Tests.cs

@@ -3,7 +3,7 @@
 public class Day09_Tests
 {
     #region MarbleGame_PlayGame
-    
+
     [Fact]
     public void MarbleGame_PlayGame__Test1()
     {
@@ -69,15 +69,15 @@ public class Day09_Tests
 
         Assert.Equal(37305, highScore);
     }
-    
+
     #endregion MarbleGame_PlayGame
-    
+
     [Fact]
     public void ResolvePart1__Test1()
     {
         Day09 day = new();
 
-        string result = day.ResolvePart1(new[] { "9 players; last marble is worth 25 points" });
+        string result = day.ResolvePart1(["9 players; last marble is worth 25 points"]);
 
         Assert.Equal("32", result);
     }
@@ -87,7 +87,7 @@ public class Day09_Tests
     {
         Day09 day = new();
 
-        string result = day.ResolvePart1(new[] { "10 players; last marble is worth 1618 points" });
+        string result = day.ResolvePart1(["10 players; last marble is worth 1618 points"]);
 
         Assert.Equal("8317", result);
     }
@@ -97,7 +97,7 @@ public class Day09_Tests
     {
         Day09 day = new();
 
-        string result = day.ResolvePart1(new[] { "13 players; last marble is worth 7999 points" });
+        string result = day.ResolvePart1(["13 players; last marble is worth 7999 points"]);
 
         Assert.Equal("146373", result);
     }
@@ -107,7 +107,7 @@ public class Day09_Tests
     {
         Day09 day = new();
 
-        string result = day.ResolvePart1(new[] { "17 players; last marble is worth 1104 points" });
+        string result = day.ResolvePart1(["17 players; last marble is worth 1104 points"]);
 
         Assert.Equal("2764", result);
     }
@@ -117,7 +117,7 @@ public class Day09_Tests
     {
         Day09 day = new();
 
-        string result = day.ResolvePart1(new[] { "21 players; last marble is worth 6111 points" });
+        string result = day.ResolvePart1(["21 players; last marble is worth 6111 points"]);
 
         Assert.Equal("54718", result);
     }
@@ -127,7 +127,7 @@ public class Day09_Tests
     {
         Day09 day = new();
 
-        string result = day.ResolvePart1(new[] { "30 players; last marble is worth 5807 points" });
+        string result = day.ResolvePart1(["30 players; last marble is worth 5807 points"]);
 
         Assert.Equal("37305", result);
     }

AdventOfCode2018.Tests/Day10_Tests.cs

@@ -7,7 +7,7 @@ public class Day10_Tests
     {
         Day10 day = new() { Width = 12, Height = 10 };
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "position=< 9,  1> velocity=< 0,  2>",
             "position=< 7,  0> velocity=<-1,  0>",
             "position=< 3, -2> velocity=<-1,  1>",
@@ -39,7 +39,7 @@ public class Day10_Tests
             "position=< 5,  9> velocity=< 1, -2>",
             "position=<14,  7> velocity=<-2,  0>",
             "position=<-3,  6> velocity=< 2, -1>",
-        });
+        ]);
 
         Assert.Equal(
             Environment.NewLine + "............" +
@@ -59,7 +59,7 @@ public class Day10_Tests
     {
         Day10 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "position=< 9,  1> velocity=< 0,  2>",
             "position=< 7,  0> velocity=<-1,  0>",
             "position=< 3, -2> velocity=<-1,  1>",
@@ -91,7 +91,7 @@ public class Day10_Tests
             "position=< 5,  9> velocity=< 1, -2>",
             "position=<14,  7> velocity=<-2,  0>",
             "position=<-3,  6> velocity=< 2, -1>",
-        });
+        ]);
 
         Assert.Equal("3", result);
     }

AdventOfCode2018.Tests/Day11_Tests.cs

@@ -59,7 +59,7 @@ public class Day11_Tests
     public void ResolvePart2__Test1()
     {
         Day11 day = new();
-        string result = day.ResolvePart2(new[] { "18" });
+        string result = day.ResolvePart2(["18"]);
         Assert.Equal("90,269,16", result);
     }
 
@@ -67,7 +67,7 @@ public class Day11_Tests
     public void ResolvePart2__Test2()
     {
         Day11 day = new();
-        string result = day.ResolvePart2(new[] { "42" });
+        string result = day.ResolvePart2(["42"]);
         Assert.Equal("232,251,12", result);
     }
 }

AdventOfCode2018.Tests/Day12_Tests.cs

@@ -7,8 +7,7 @@ public class Day12_Tests
     {
         Day12 day = new();
 
-        string result = day.ResolvePart1(new[]
+        string result = day.ResolvePart1([
-        {
             "initial state: #..#.#..##......###...###",
             "",
             "...## => #",
@@ -25,7 +24,7 @@ public class Day12_Tests
             "###.. => #",
             "###.# => #",
             "####. => #",
-        });
+        ]);
 
         Assert.Equal("325", result);
     }

AdventOfCode2018.Tests/Day13_Tests.cs

@@ -7,7 +7,7 @@ public class Day13_Tests
     {
         Day13 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "|",
             "v",
             "|",
@@ -15,7 +15,7 @@ public class Day13_Tests
             "|",
             "^",
             "|",
-        });
+        ]);
 
         Assert.Equal("0,3", result);
     }
@@ -25,14 +25,14 @@ public class Day13_Tests
     {
         Day13 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             @"/->-\        ",
             @"|   |  /----\",
             @"| /-+--+-\  |",
             @"| | |  | v  |",
             @"\-+-/  \-+--/",
             @"  \------/   ",
-        });
+        ]);
 
         Assert.Equal("7,3", result);
     }
@@ -42,7 +42,7 @@ public class Day13_Tests
     {
         Day13 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             @"/>-<\  ",
             @"|   |  ",
             @"| /<+-\",
@@ -50,7 +50,7 @@ public class Day13_Tests
             @"\>+</ |",
             @"  |   ^",
             @"  \<->/",
-        });
+        ]);
 
         Assert.Equal("6,4", result);
     }

AdventOfCode2018.Tests/Day14_Tests.cs

@@ -9,7 +9,7 @@ public class Day14_Tests
     {
         Day14 day = new();
 
-        string result = day.ResolvePart1(new[] { "9", });
+        string result = day.ResolvePart1(["9"]);
 
         Assert.Equal("5158916779", result);
     }
@@ -19,7 +19,7 @@ public class Day14_Tests
     {
         Day14 day = new();
 
-        string result = day.ResolvePart1(new[] { "5", });
+        string result = day.ResolvePart1(["5"]);
 
         Assert.Equal("0124515891", result);
     }
@@ -29,7 +29,7 @@ public class Day14_Tests
     {
         Day14 day = new();
 
-        string result = day.ResolvePart1(new[] { "18", });
+        string result = day.ResolvePart1(["18"]);
 
         Assert.Equal("9251071085", result);
     }
@@ -39,7 +39,7 @@ public class Day14_Tests
     {
         Day14 day = new();
 
-        string result = day.ResolvePart1(new[] { "2018", });
+        string result = day.ResolvePart1(["2018"]);
 
         Assert.Equal("5941429882", result);
     }
@@ -53,7 +53,7 @@ public class Day14_Tests
     {
         Day14 day = new();
 
-        string result = day.ResolvePart2(new[] { "51589", });
+        string result = day.ResolvePart2(["51589"]);
 
         Assert.Equal("9", result);
     }
@@ -63,7 +63,7 @@ public class Day14_Tests
     {
         Day14 day = new();
 
-        string result = day.ResolvePart2(new[] { "01245", });
+        string result = day.ResolvePart2(["01245"]);
 
         Assert.Equal("5", result);
     }
@@ -73,7 +73,7 @@ public class Day14_Tests
     {
         Day14 day = new();
 
-        string result = day.ResolvePart2(new[] { "92510", });
+        string result = day.ResolvePart2(["92510"]);
 
         Assert.Equal("18", result);
     }
@@ -83,7 +83,7 @@ public class Day14_Tests
     {
         Day14 day = new();
 
-        string result = day.ResolvePart2(new[] { "59414", });
+        string result = day.ResolvePart2(["59414"]);
 
         Assert.Equal("2018", result);
     }

AdventOfCode2018.Tests/Day15_Tests.cs

@@ -9,7 +9,7 @@ public class Day15_Tests
     {
         Day15 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "#######",
             "#.G...#",
             "#...EG#",
@@ -17,7 +17,7 @@ public class Day15_Tests
             "#..G#E#",
             "#.....#",
             "#######",
-        });
+        ]);
 
         Assert.Equal("27730", result);
     }
@@ -27,7 +27,7 @@ public class Day15_Tests
     {
         Day15 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "#######",
             "#G..#E#",
             "#E#E.E#",
@@ -35,17 +35,17 @@ public class Day15_Tests
             "#...#E#",
             "#...E.#",
             "#######",
-        });
+        ]);
 
         Assert.Equal("36334", result);
     }
-        
+
     [Fact]
     public void ResolvePart1__Test3()
     {
         Day15 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "#######",
             "#E..EG#",
             "#.#G.E#",
@@ -53,7 +53,7 @@ public class Day15_Tests
             "#G..#.#",
             "#..E#.#",
             "#######",
-        });
+        ]);
 
         Assert.Equal("39514", result);
     }
@@ -63,7 +63,7 @@ public class Day15_Tests
     {
         Day15 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "#######",
             "#E.G#.#",
             "#.#G..#",
@@ -71,7 +71,7 @@ public class Day15_Tests
             "#G..#.#",
             "#...E.#",
             "#######",
-        });
+        ]);
 
         Assert.Equal("27755", result);
     }
@@ -81,7 +81,7 @@ public class Day15_Tests
     {
         Day15 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "#######",
             "#.E...#",
             "#.#..G#",
@@ -89,7 +89,7 @@ public class Day15_Tests
             "#E#G#G#",
             "#...#G#",
             "#######",
-        });
+        ]);
 
         Assert.Equal("28944", result);
     }
@@ -99,7 +99,7 @@ public class Day15_Tests
     {
         Day15 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "#########",
             "#G......#",
             "#.E.#...#",
@@ -109,7 +109,7 @@ public class Day15_Tests
             "#.G...G.#",
             "#.....G.#",
             "#########",
-        });
+        ]);
 
         Assert.Equal("18740", result);
     }
@@ -123,7 +123,7 @@ public class Day15_Tests
     {
         Day15 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "#######",
             "#.G...#",
             "#...EG#",
@@ -131,17 +131,17 @@ public class Day15_Tests
             "#..G#E#",
             "#.....#",
             "#######",
-        });
+        ]);
 
         Assert.Equal("4988", result);
     }
-        
+
     [Fact]
     public void ResolvePart2__Test3()
     {
         Day15 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "#######",
             "#E..EG#",
             "#.#G.E#",
@@ -149,7 +149,7 @@ public class Day15_Tests
             "#G..#.#",
             "#..E#.#",
             "#######",
-        });
+        ]);
 
         Assert.Equal("31284", result);
     }
@@ -159,7 +159,7 @@ public class Day15_Tests
     {
         Day15 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "#######",
             "#E.G#.#",
             "#.#G..#",
@@ -167,7 +167,7 @@ public class Day15_Tests
             "#G..#.#",
             "#...E.#",
             "#######",
-        });
+        ]);
 
         Assert.Equal("3478", result);
     }
@@ -177,7 +177,7 @@ public class Day15_Tests
     {
         Day15 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "#######",
             "#.E...#",
             "#.#..G#",
@@ -185,7 +185,7 @@ public class Day15_Tests
             "#E#G#G#",
             "#...#G#",
             "#######",
-        });
+        ]);
 
         Assert.Equal("6474", result);
     }
@@ -195,7 +195,7 @@ public class Day15_Tests
     {
         Day15 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "#########",
             "#G......#",
             "#.E.#...#",
@@ -205,7 +205,7 @@ public class Day15_Tests
             "#.G...G.#",
             "#.....G.#",
             "#########",
-        });
+        ]);
 
         Assert.Equal("1140", result);
     }

AdventOfCode2018.Tests/Day16_Tests.cs

@@ -7,7 +7,7 @@ public class Day16_Tests
     {
         Day16 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "Before: [3, 2, 1, 1]",
             "9 2 1 2",
             "After:  [3, 2, 2, 1]",
@@ -18,7 +18,7 @@ public class Day16_Tests
             "",
             "",
             "Garbage",
-        });
+        ]);
 
         Assert.Equal("2", result);
     }

AdventOfCode2018.Tests/Day23_Tests.cs

@@ -7,7 +7,7 @@ public class Day23_Tests
     {
         Day23 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "pos=<0,0,0>, r=4",
             "pos=<1,0,0>, r=1",
             "pos=<4,0,0>, r=3",
@@ -17,7 +17,7 @@ public class Day23_Tests
             "pos=<1,1,1>, r=1",
             "pos=<1,1,2>, r=1",
             "pos=<1,3,1>, r=1",
-        });
+        ]);
 
         Assert.Equal("7", result);
     }
@@ -27,14 +27,14 @@ public class Day23_Tests
     {
         Day23 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "pos=<10,12,12>, r=2",
             "pos=<12,14,12>, r=2",
             "pos=<16,12,12>, r=4",
             "pos=<14,14,14>, r=6",
             "pos=<50,50,50>, r=200",
             "pos=<10,10,10>, r=5",
-        });
+        ]);
 
         Assert.Equal("36", result);
     }

AdventOfCode2018.Tests/packages.config

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="MSTest.TestAdapter" version="1.4.0" targetFramework="net461" />
+    <package id="MSTest.TestAdapter" version="1.4.0" targetFramework="net461"/>
-  <package id="MSTest.TestFramework" version="1.4.0" targetFramework="net461" />
+    <package id="MSTest.TestFramework" version="1.4.0" targetFramework="net461"/>
 </packages>

AdventOfCode2018/AdventOfCode2018.csproj

@@ -1,20 +1,21 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <PropertyGroup>
+    <PropertyGroup>
-    <OutputType>Exe</OutputType>
+        <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
+        <ImplicitUsings>enable</ImplicitUsings>
-    <RootNamespace>AdventOfCode2018</RootNamespace>
+        <Nullable>enable</Nullable>
-  </PropertyGroup>
+        <RootNamespace>AdventOfCode2018</RootNamespace>
+    </PropertyGroup>
 
-  <ItemGroup>
+    <ItemGroup>
-    <None Update="inputs\*">
+        <None Update="inputs\*">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+            <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </None>
+        </None>
-  </ItemGroup>
+    </ItemGroup>
 
-  <ItemGroup>
+    <ItemGroup>
-    <ProjectReference Include="..\AdventOfCode.Common\AdventOfCode.Common.csproj" />
+        <ProjectReference Include="..\AdventOfCode.Common\AdventOfCode.Common.csproj"/>
-  </ItemGroup>
+    </ItemGroup>
 
 </Project>

AdventOfCode2018/Day01.cs

@@ -63,8 +63,7 @@ public class Day01 : IDay
         int accumulator = 0;
         foreach (string input in inputs)
         {
-            int intInput;
+            if (int.TryParse(input.Substring(1), out int intInput))
-            if (int.TryParse(input.Substring(1), out intInput))
             {
                 if (input[0] == '-')
                 {
@@ -83,15 +82,14 @@ public class Day01 : IDay
     public string ResolvePart2(string[] inputs)
     {
         int accumulator = 0;
-        List<int> accumulatorHistory = new();
+        List<int> accumulatorHistory = [];
         int? repeatedAccumulator = null;
         while (repeatedAccumulator == null)
         {
             foreach (string input in inputs)
             {
                 accumulatorHistory.Add(accumulator);
-                int intInput;
+                if (int.TryParse(input.Substring(1), out int intInput))
-                if (int.TryParse(input.Substring(1), out intInput))
                 {
                     if (input[0] == '-')
                     {
@@ -110,6 +108,6 @@ public class Day01 : IDay
                 }
             }
         }
-        return repeatedAccumulator.ToString();
+        return repeatedAccumulator.ToString() ?? string.Empty;
     }
 }

AdventOfCode2018/Day02.cs

@@ -50,7 +50,7 @@ What letters are common between the two correct box IDs? (In the example above,
 
 public class Day02 : IDay
 {
-    private int CountOccurrencesOfLetter(string text, char letter)
+    private static int CountOccurrencesOfLetter(string text, char letter)
     {
         return text.Count(c => (c == letter));
     }
@@ -75,7 +75,7 @@ public class Day02 : IDay
         int tripletsCount = 0;
         foreach (string input in inputs)
         {
-            var hasPairsAndTriplets = HasPairsAndTriplets(input);
+            Tuple<bool, bool> hasPairsAndTriplets = HasPairsAndTriplets(input);
             if (hasPairsAndTriplets.Item1) { pairsCount++; }
             if (hasPairsAndTriplets.Item2) { tripletsCount++; }
         }
@@ -104,11 +104,10 @@ public class Day02 : IDay
         {
             for (int j = (i + 1); j < inputs.Length; j++)
             {
-                var result = CompareIDPair(inputs[i], inputs[j]);
+                Tuple<int, string> result = CompareIDPair(inputs[i], inputs[j]);
                 if (result.Item1 == 1) { return result.Item2; }
             }
         }
         return string.Empty;
     }
-
 }

AdventOfCode2018/Day03.cs

@@ -60,7 +60,7 @@ public class Day03 : IDay
 {
     public string ResolvePart1(string[] inputs)
     {
-        List<Claim> claims = inputs.Select(i => Claim.FromString(i)).ToList();
+        List<Claim> claims = inputs.Select(Claim.FromString).ToList();
 
         const int edgeSize = 1000;
         int[,] cells = new int[edgeSize, edgeSize];
@@ -92,9 +92,9 @@ public class Day03 : IDay
 
     public string ResolvePart2(string[] inputs)
     {
-        List<Claim> claims = inputs.Select(i => Claim.FromString(i)).ToList();
+        List<Claim> claims = inputs.Select(Claim.FromString).ToList();
 
-        Claim unoverlappingClaim = null;
+        Claim? unOverlappingClaim = null;
         for (int i = 0; i < claims.Count; i++)
         {
             bool overlaps = false;
@@ -109,29 +109,43 @@ public class Day03 : IDay
             }
             if (overlaps == false)
             {
-                unoverlappingClaim = claims[i];
+                unOverlappingClaim = claims[i];
                 break;
             }
         }
-        return unoverlappingClaim.ID.ToString();
+        return unOverlappingClaim?.ID.ToString() ?? string.Empty;
 
     }
 
     public class Claim
     {
-        public int ID { get; set; }
+        public int ID { get; private set; }
 
-        public int Left { get; set; }
+        public int Left { get; private set; }
-        public int Top { get; set; }
+        public int Top { get; private set; }
 
-        public int Width { get; set; }
+        public int Width { get; private set; }
-        public int Height { get; set; }
+        public int Height { get; private set; }
 
-        public int MinX { get { return Left; } }
+        private int MinX
-        public int MaxX { get { return Left + Width; } }
+        {
+            get { return Left; }
+        }
 
-        public int MinY { get { return Top; } }
+        private int MaxX
-        public int MaxY { get { return Top + Height; } }
+        {
+            get { return Left + Width; }
+        }
+
+        private int MinY
+        {
+            get { return Top; }
+        }
+
+        private int MaxY
+        {
+            get { return Top + Height; }
+        }
 
         public int GetArea()
         {
@@ -141,7 +155,7 @@ public class Day03 : IDay
         public static Claim FromString(string strClaim)
         {
             Claim claim = new();
-            string[] parts = strClaim.Split(new[] { " @ ", ",", ": ", "x", }, StringSplitOptions.None);
+            string[] parts = strClaim.Split([" @ ", ",", ": ", "x"], StringSplitOptions.None);
             claim.ID = Convert.ToInt32(parts[0].Substring(1));
             claim.Left = Convert.ToInt32(parts[1]);
             claim.Top = Convert.ToInt32(parts[2]);

AdventOfCode2018/Day04.cs

@@ -68,14 +68,14 @@ public class Day04 : IDay
     public string ResolvePart1(string[] inputs)
     {
         List<GuardEvent> guardEvents = GuardEvent.FromStringArray(inputs);
-        Dictionary<int, GuardSleepHistogram> dictFullHistogram = BuildFullHistorgram(guardEvents);
+        Dictionary<int, GuardSleepHistogram> dictFullHistogram = BuildFullHistogram(guardEvents);
 
         // Find sleepier guard
-        GuardSleepHistogram highestSleeperHistogram = null;
+        GuardSleepHistogram? highestSleeperHistogram = null;
         long highestTotalSleep = long.MinValue;
         foreach (GuardSleepHistogram guardHistogram in dictFullHistogram.Values)
         {
-            int totalSleep = guardHistogram.SleepOnMunute.Sum();
+            int totalSleep = guardHistogram.SleepOnMinute.Sum();
 
             if (totalSleep > highestTotalSleep)
             {
@@ -83,16 +83,17 @@ public class Day04 : IDay
                 highestTotalSleep = totalSleep;
             }
         }
+        if (highestSleeperHistogram == null) { return string.Empty; }
 
         // Find sleepier minute
         int maxSleepMinute = int.MinValue;
         int maxSleepMinuteValue = int.MinValue;
         for (int i = 0; i < GuardSleepHistogram.MinutesOnHour; i++)
         {
-            if (highestSleeperHistogram.SleepOnMunute[i] > maxSleepMinuteValue)
+            if (highestSleeperHistogram.SleepOnMinute[i] > maxSleepMinuteValue)
             {
                 maxSleepMinute = i;
-                maxSleepMinuteValue = highestSleeperHistogram.SleepOnMunute[i];
+                maxSleepMinuteValue = highestSleeperHistogram.SleepOnMinute[i];
             }
         }
 
@@ -103,7 +104,7 @@ public class Day04 : IDay
     public string ResolvePart2(string[] inputs)
     {
         List<GuardEvent> guardEvents = GuardEvent.FromStringArray(inputs);
-        Dictionary<int, GuardSleepHistogram> dictFullHistogram = BuildFullHistorgram(guardEvents);
+        Dictionary<int, GuardSleepHistogram> dictFullHistogram = BuildFullHistogram(guardEvents);
 
         int selectedGuardID = int.MinValue;
         int selectedMinute = int.MinValue;
@@ -112,9 +113,9 @@ public class Day04 : IDay
         {
             foreach (GuardSleepHistogram guardHistogram in dictFullHistogram.Values)
             {
-                if (guardHistogram.SleepOnMunute[i] > maxSleepMinuteValue)
+                if (guardHistogram.SleepOnMinute[i] > maxSleepMinuteValue)
                 {
-                    maxSleepMinuteValue = guardHistogram.SleepOnMunute[i];
+                    maxSleepMinuteValue = guardHistogram.SleepOnMinute[i];
                     selectedGuardID = guardHistogram.ID;
                     selectedMinute = i;
                 }
@@ -125,7 +126,7 @@ public class Day04 : IDay
         return result.ToString();
     }
 
-    private static Dictionary<int, GuardSleepHistogram> BuildFullHistorgram(List<GuardEvent> guardEvents)
+    private static Dictionary<int, GuardSleepHistogram> BuildFullHistogram(List<GuardEvent> guardEvents)
     {
         Dictionary<int, GuardSleepHistogram> dictFullHistogram = new();
         foreach (IGrouping<int, GuardEvent> group in guardEvents.GroupBy(guardEvent => guardEvent.Date.DayOfYear))
@@ -156,16 +157,12 @@ public class Day04 : IDay
 
             foreach (GuardSleepHistogram dayGuardHistogram in dictDayHistogram.Values)
             {
-                GuardSleepHistogram guardHistogram;
+                if (dictFullHistogram.TryGetValue(dayGuardHistogram.ID, out GuardSleepHistogram? guardHistogram))
-                if (dictFullHistogram.ContainsKey(dayGuardHistogram.ID))
                 {
-                    guardHistogram = dictFullHistogram[dayGuardHistogram.ID];
                     guardHistogram.AddHistogram(dayGuardHistogram);
+                    continue;
                 }
-                else
+                dictFullHistogram.Add(dayGuardHistogram.ID, dayGuardHistogram);
-                {
-                    dictFullHistogram.Add(dayGuardHistogram.ID, dayGuardHistogram);
-                }
             }
         }
 
@@ -181,14 +178,14 @@ public class Day04 : IDay
 
     public class GuardEvent
     {
-        public DateTime Date { get; set; }
+        public DateTime Date { get; private set; }
-        public int? ID { get; set; }
+        public int? ID { get; private set; }
-        public GuardEventType Type { get; set; }
+        public GuardEventType Type { get; private set; }
 
         public static GuardEvent FromString(string strEvent)
         {
             GuardEvent guardEvent = new();
-            string[] parts = strEvent.Split(new[] { "[", "-", " ", ":", "]", "#", }, StringSplitOptions.RemoveEmptyEntries);
+            string[] parts = strEvent.Split(["[", "-", " ", ":", "]", "#"], StringSplitOptions.RemoveEmptyEntries);
             guardEvent.Date = new DateTime(
                 Convert.ToInt32(parts[0]),
                 Convert.ToInt32(parts[1]),
@@ -216,7 +213,7 @@ public class Day04 : IDay
         public static List<GuardEvent> FromStringArray(string[] strEvents)
         {
             List<GuardEvent> guardEvents = strEvents
-                .Select(strEvent => FromString(strEvent))
+                .Select(FromString)
                 .OrderBy(guardEvent => guardEvent.Date)
                 .ToList();
 
@@ -240,14 +237,14 @@ public class Day04 : IDay
     public class GuardSleepHistogram
     {
         public const int MinutesOnHour = 60;
-        public int ID { get; set; }
+        public int ID { get; init; }
-        public int[] SleepOnMunute { get; } = new int[MinutesOnHour];
+        public int[] SleepOnMinute { get; } = new int[MinutesOnHour];
 
         public void FallSleep(int minute)
         {
             for (int i = minute; i < MinutesOnHour; i++)
             {
-                SleepOnMunute[i] = 1;
+                SleepOnMinute[i] = 1;
             }
         }
 
@@ -255,7 +252,7 @@ public class Day04 : IDay
         {
             for (int i = minute; i < MinutesOnHour; i++)
             {
-                SleepOnMunute[i] = 0;
+                SleepOnMinute[i] = 0;
             }
         }
 
@@ -263,7 +260,7 @@ public class Day04 : IDay
         {
             for (int i = 0; i < MinutesOnHour; i++)
             {
-                SleepOnMunute[i] += histogram.SleepOnMunute[i];
+                SleepOnMinute[i] += histogram.SleepOnMinute[i];
             }
         }
     }

AdventOfCode2018/Day05.cs

@@ -108,7 +108,7 @@ public class Day05 : IDay
     public string ResolvePart2(string[] inputs)
     {
         string input = inputs[0];
-        List<char> allUnitTypes = input.Select(c => char.ToLower(c)).Distinct().ToList();
+        List<char> allUnitTypes = input.Select(char.ToLower).Distinct().ToList();
 
         int minPolymerLenght = int.MaxValue;
         foreach (char unitType in allUnitTypes)

AdventOfCode2018/Day06.cs

@@ -96,7 +96,8 @@ public class Day06 : IDay
     {
         return inputs
             .Where(input => string.IsNullOrEmpty(input) == false)
-            .Select(input => ChronoPoint.FromString(input))
+            .Select(ChronoPoint.FromString)
+            .OfType<ChronoPoint>()
             .ToList();
     }
 
@@ -183,12 +184,12 @@ public class Day06 : IDay
         return areaInRange;
     }
 
-    public int DistanceThresold { get; set; } = 10000;
+    public int DistanceThreshold { get; init; } = 10000;
 
     public string ResolvePart2(string[] inputs)
     {
         List<ChronoPoint> points = InputsToPoints(inputs);
-        int areaInRange = AreaInThresold(points, DistanceThresold);
+        int areaInRange = AreaInThresold(points, DistanceThreshold);
         return areaInRange.ToString();
     }
 
@@ -197,10 +198,10 @@ public class Day06 : IDay
         public int X { get; set; }
         public int Y { get; set; }
 
-        public static ChronoPoint FromString(string strPoint)
+        public static ChronoPoint? FromString(string strPoint)
         {
             if (string.IsNullOrEmpty(strPoint)) { return null; }
-            string[] parts = strPoint.Split(new[] { ", ", }, StringSplitOptions.RemoveEmptyEntries);
+            string[] parts = strPoint.Split([", "], StringSplitOptions.RemoveEmptyEntries);
             if (parts.Length < 2) { return null; }
             ChronoPoint point = new() {
                 X = Convert.ToInt32(parts[0]),

AdventOfCode2018/Day07.cs

@@ -89,11 +89,11 @@ public class Day07 : IDay
         foreach (string input in inputs)
         {
             if (string.IsNullOrEmpty(input)) { continue; }
-            string[] parts = input.Split(new[] {
+            string[] parts = input.Split([
                 "Step ",
                 " must be finished before step ",
                 " can begin.",
-            }, StringSplitOptions.RemoveEmptyEntries);
+            ], StringSplitOptions.RemoveEmptyEntries);
             instructions.AddNodeRelation(parts[1].ToUpper(), parts[0].ToUpper());
         }
         foreach (InstructionNode node in instructions.Nodes.Values)
@@ -118,8 +118,8 @@ public class Day07 : IDay
         return sbInstructions.ToString();
     }
 
-    public int BaseCost { get; set; } = 60;
+    public int BaseCost { get; init; } = 60;
-    public int NumberOfWorkers { get; set; } = 5;
+    public int NumberOfWorkers { get; init; } = 5;
 
     public string ResolvePart2(string[] inputs)
     {
@@ -128,11 +128,11 @@ public class Day07 : IDay
         return totalElapsedTime.ToString();
     }
 
-    public class InstructionNode
+    public class InstructionNode(string nodeID)
     {
-        public string NodeID { get; set; }
+        public string NodeID { get; init; } = nodeID;
 
-        public List<string> PreviousNodeIDs { get; } = new();
+        public List<string> PreviousNodeIDs { get; } = [];
 
         public int Cost { get; set; }
 
@@ -148,22 +148,18 @@ public class Day07 : IDay
         }
     }
 
-    public class Instructions
+    private class Instructions
     {
         public Dictionary<string, InstructionNode> Nodes { get; } = new();
 
-        public InstructionNode GetNode(string nodeID)
+        private InstructionNode GetNode(string nodeID)
         {
-            InstructionNode node = null;
+            if (Nodes.TryGetValue(nodeID, out InstructionNode? nodeAux))
-            if (Nodes.ContainsKey(nodeID))
             {
-                node = Nodes[nodeID];
+                return nodeAux;
-            }
-            else
-            {
-                node = new InstructionNode { NodeID = nodeID, };
-                Nodes.Add(nodeID, node);
             }
+            InstructionNode node = new(nodeID);
+            Nodes.Add(nodeID, node);
             return node;
         }
 
@@ -176,7 +172,7 @@ public class Day07 : IDay
 
         public List<InstructionNode> SortInstructions()
         {
-            List<InstructionNode> finalNodes = new();
+            List<InstructionNode> finalNodes = [];
 
             foreach (InstructionNode node in Nodes.Values)
             {
@@ -194,7 +190,8 @@ public class Day07 : IDay
                     .ToList();
                 if (unusedNodes.Count > 0)
                 {
-                    InstructionNode node = unusedNodes.FirstOrDefault();
+                    InstructionNode? node = unusedNodes.FirstOrDefault();
+                    if (node == null) { continue; }
                     finalNodes.Add(node);
                     node.Used = true;
                 }
@@ -204,8 +201,8 @@ public class Day07 : IDay
 
         private class SimulatedWorker
         {
-            public InstructionNode CurrentInstruction { get; set; }
+            public InstructionNode? CurrentInstruction { get; private set; }
-            public int ElapsedTime { get; set; }
+            private int ElapsedTime { get; set; }
 
             public void SetInstruction(InstructionNode instruction)
             {
@@ -242,7 +239,6 @@ public class Day07 : IDay
                 workers.Add(new SimulatedWorker());
             }
 
-            bool anyWorkerWitoutWork;
             do
             {
                 bool anyWorkDone = false;
@@ -255,8 +251,8 @@ public class Day07 : IDay
                 }
                 if (anyWorkDone) { totalElapsedTime++; }
 
-                anyWorkerWitoutWork = workers.Any(w => w.CurrentInstruction == null);
+                bool anyWorkerWithoutWork = workers.Any(w => w.CurrentInstruction == null);
-                if (anyWorkerWitoutWork)
+                if (anyWorkerWithoutWork)
                 {
                     List<InstructionNode> unusedNodes = Nodes.Values
                         .Where(n =>

AdventOfCode2018/Day08.cs

@@ -77,13 +77,13 @@ public class Day08 : IDay
 
     public class IntStream
     {
-        private int[] _values;
+        private readonly int[] _values;
         private int _index;
 
         public IntStream(string strValues)
         {
             _values = strValues
-                .Split(new[] { " ", }, StringSplitOptions.RemoveEmptyEntries)
+                .Split([" "], StringSplitOptions.RemoveEmptyEntries)
                 .Select(strVal => Convert.ToInt32(strVal))
                 .ToArray();
             _index = 0;
@@ -99,9 +99,9 @@ public class Day08 : IDay
 
     public class ChronoLicenceNode
     {
-        public List<ChronoLicenceNode> Childs { get; } = new();
+        public List<ChronoLicenceNode> Childs { get; } = [];
 
-        public List<int> Metadata { get; } = new();
+        public List<int> Metadata { get; } = [];
 
         public static ChronoLicenceNode BuildFromIntStream(IntStream stream)
         {

AdventOfCode2018/Day09.cs

@@ -75,7 +75,7 @@ public class Day09 : IDay
 
     private static string CalculateHighScore(string input, long factor)
     {
-        string[] parts = input.Split(new[] { " players; last marble is worth ", " points" }, StringSplitOptions.RemoveEmptyEntries);
+        string[] parts = input.Split([" players; last marble is worth ", " points"], StringSplitOptions.RemoveEmptyEntries);
         long numberOfPlayers = Convert.ToInt32(parts[0]);
         long lastMarble = Convert.ToInt32(parts[1]) * factor;
         MarbleGame marbleGame = new();
@@ -86,17 +86,17 @@ public class Day09 : IDay
 
     public class Marble
     {
-        public long Value { get; set; }
+        public long Value { get; init; }
-        public Marble Previous { get; set; }
+        public Marble? Previous { get; set; }
-        public Marble Next { get; set; }
+        public Marble? Next { get; set; }
     }
 
     public class MarbleGame
     {
-        public Dictionary<long, long> Scores { get; } = new();
+        private Dictionary<long, long> Scores { get; } = new();
 
-        private Marble _firstMarble;
+        private Marble? _firstMarble;
-        private Marble _currentMarble;
+        private Marble? _currentMarble;
         private long _currentPlayer;
 
         private const long PointValueMultiple = 23;
@@ -119,20 +119,34 @@ public class Day09 : IDay
                 Marble newMarble = new() { Value = i + 1 };
                 if ((newMarble.Value % PointValueMultiple) > 0)
                 {
-                    Marble previousMarble = _currentMarble.Next;
+                    Marble? previousMarble = _currentMarble?.Next;
-                    Marble nextMarble = previousMarble.Next;
+                    Marble? nextMarble = previousMarble?.Next;
                     newMarble.Previous = previousMarble;
                     newMarble.Next = nextMarble;
-                    previousMarble.Next = newMarble;
+                    if(previousMarble != null)
-                    nextMarble.Previous = newMarble;
+                    {
+                        previousMarble.Next = newMarble;
+                    }
+                    if(nextMarble != null)
+                    {
+                        nextMarble.Previous = newMarble;
+                    }
                     _currentMarble = newMarble;
                 }
                 else
                 {
-                    Marble marbleToRemove = _currentMarble.Previous.Previous.Previous.Previous.Previous.Previous.Previous;
+                    Marble? marbleToRemove = _currentMarble?.Previous?.Previous?.Previous?.Previous?.Previous?.Previous?.Previous;
-                    _currentMarble = marbleToRemove.Next;
+                    _currentMarble = marbleToRemove?.Next;
-                    marbleToRemove.Previous.Next = marbleToRemove.Next;
+                    if (marbleToRemove == null) { continue; }
-                    marbleToRemove.Next.Previous = marbleToRemove.Previous;
+                    
+                    if(marbleToRemove.Previous != null)
+                    {
+                        marbleToRemove.Previous.Next = marbleToRemove.Next;
+                    }
+                    if (marbleToRemove.Next != null)
+                    {
+                        marbleToRemove.Next.Previous = marbleToRemove.Previous;
+                    }
 
                     long currentPlayerScore = Scores[_currentPlayer] + (newMarble.Value + marbleToRemove.Value);
                     Scores[_currentPlayer] = currentPlayerScore;
@@ -141,22 +155,17 @@ public class Day09 : IDay
             }
         }
 
-        public void PrintStatus()
+        private void PrintStatus()
         {
             Console.Write("[{0}] ", _currentPlayer);
-            Marble marble = _firstMarble;
+            Marble? marble = _firstMarble;
             do
             {
-                if (_currentMarble.Value == marble.Value)
+                Console.Write(_currentMarble?.Value == marble?.Value 
-                {
+                    ? "({0}) " 
-                    Console.Write("({0}) ", marble.Value);
+                    : "{0} ", marble?.Value);
-                }
+                marble = marble?.Next;
-                else
+            } while (marble != null && marble.Value != 0);
-                {
-                    Console.Write("{0} ", marble.Value);
-                }
-                marble = marble.Next;
-            } while (marble.Value != 0);
             Console.WriteLine();
         }
 

AdventOfCode2018/Day10.cs

@@ -156,13 +156,13 @@ Impressed by your sub-hour communication capabilities, the Elves are curious: ex
 
 public class Day10 : IDay
 {
-    public int Width { get; set; } = 65;
+    public int Width { get; init; } = 65;
-    public int Height { get; set; } = 12;
+    public int Height { get; init; } = 12;
 
     public string ResolvePart1(string[] inputs)
     {
         LightField lightField = new(inputs);
-        int t = lightField.SearchSmallerBoundindBox();
+        int t = lightField.SearchSmallerBoundingBox();
         string result = lightField.Render(t, Width, Height);
         return result;
     }
@@ -170,20 +170,20 @@ public class Day10 : IDay
     public string ResolvePart2(string[] inputs)
     {
         LightField lightField = new(inputs);
-        int t = lightField.SearchSmallerBoundindBox();
+        int t = lightField.SearchSmallerBoundingBox();
         return t.ToString();
     }
 
     public class LightPoint
     {
-        public int X { get; set; }
+        private int X { get; init; }
-        public int Y { get; set; }
+        private int Y { get; init; }
-        public int VX { get; set; }
+        private int VX { get; init; }
-        public int VY { get; set; }
+        private int VY { get; init; }
 
         public static LightPoint FromString(string strPoint)
         {
-            string[] parts = strPoint.Split(new[] { "position=<", " ", ",", "> velocity=<", ">" }, StringSplitOptions.RemoveEmptyEntries);
+            string[] parts = strPoint.Split(["position=<", " ", ",", "> velocity=<", ">"], StringSplitOptions.RemoveEmptyEntries);
             LightPoint point = new() {
                 X = Convert.ToInt32(parts[0]),
                 Y = Convert.ToInt32(parts[1]),
@@ -204,16 +204,11 @@ public class Day10 : IDay
         }
     }
 
-    public class LightField
+    private class LightField(string[] strPoints)
     {
-        private readonly List<LightPoint> _points;
+        private readonly List<LightPoint> _points = strPoints.Select(LightPoint.FromString).ToList();
 
-        public LightField(string[] strPoints)
+        public int SearchSmallerBoundingBox()
-        {
-            _points = strPoints.Select(strPoint => LightPoint.FromString(strPoint)).ToList();
-        }
-
-        public int SearchSmallerBoundindBox()
         {
             int minHeight = int.MaxValue;
             int minT = 0;
@@ -288,14 +283,7 @@ public class Day10 : IDay
                 sb.AppendLine();
                 for (int i = 0; i < width; i++)
                 {
-                    if (field[i, j] > 0)
+                    sb.Append(field[i, j] > 0 ? "#" : ".");
-                    {
-                        sb.Append("#");
-                    }
-                    else
-                    {
-                        sb.Append(".");
-                    }
                 }
             }
             return sb.ToString();

AdventOfCode2018/Day11.cs

@@ -190,7 +190,7 @@ public class Day11 : IDay
         return powerLevel;
     }
 
-    public static void SearchBestRegion(int width, int height, int serial, out int x, out int y, out int size)
+    private static void SearchBestRegion(int width, int height, int serial, out int x, out int y, out int size)
     {
         int[,] summationFiled = GenerateSumationField(width, height, serial);
         int bestPowerLevel = int.MinValue;

AdventOfCode2018/Day12.cs

@@ -96,23 +96,23 @@ public class Day12 : IDay
 
     private class PlantRule
     {
-        public bool Minus2 { get; set; }
+        public bool Minus2 { get; init; }
-        public bool Minus1 { get; set; }
+        public bool Minus1 { get; init; }
-        public bool Current { get; set; }
+        public bool Current { get; init; }
-        public bool Plus1 { get; set; }
+        public bool Plus1 { get; init; }
-        public bool Plus2 { get; set; }
+        public bool Plus2 { get; init; }
 
-        public bool Result { get; set; }
+        public bool Result { get; init; }
     }
 
     private const int SideMargin = 5;
     private const int SideProcessMargin = 2;
 
-    private List<bool> _initialState = new();
+    private readonly List<bool> _initialState = [];
-    private List<PlantRule> _rules = new();
+    private readonly List<PlantRule> _rules = [];
     private long _offsetField;
-    private bool[] _field;
+    private bool[] _field = [];
-    private bool[] _workField;
+    private bool[] _workField = [];
 
     private void Initialize(string[] inputs)
     {
@@ -126,9 +126,8 @@ public class Day12 : IDay
         for (int i = 2; i < inputs.Length; i++)
         {
             if (string.IsNullOrEmpty(inputs[i])) { continue; }
-            string[] parts = inputs[i].Split(new[] { " => " }, StringSplitOptions.RemoveEmptyEntries);
+            string[] parts = inputs[i].Split([" => "], StringSplitOptions.RemoveEmptyEntries);
-            _rules.Add(new PlantRule
+            _rules.Add(new PlantRule {
-            {
                 Minus2 = (parts[0][0] == '#'),
                 Minus1 = (parts[0][1] == '#'),
                 Current = (parts[0][2] == '#'),
@@ -151,9 +150,7 @@ public class Day12 : IDay
 
     private void SwapFields()
     {
-        bool[] aux = _field;
+        (_field, _workField) = (_workField, _field);
-        _field = _workField;
-        _workField = aux;
     }
 
     private void RecenterField()
@@ -236,8 +233,7 @@ public class Day12 : IDay
                     rule.Minus1 == minus1 &&
                     rule.Current == current &&
                     rule.Plus1 == plus1 &&
-                    rule.Plus2 == plus2 &&
+                    rule.Plus2 == plus2
-                    true
                 )
                 {
                     result = rule.Result;

AdventOfCode2018/Day13.cs

@@ -217,7 +217,7 @@ public class Day13 : IDay
     public string ResolvePart1(string[] inputs)
     {
         Initialize(inputs);
-        Train collidingTrain;
+        Train? collidingTrain;
         do
         {
             if (ShowProgress) { ShowGrid(); }
@@ -229,7 +229,7 @@ public class Day13 : IDay
     public string ResolvePart2(string[] inputs)
     {
         Initialize(inputs);
-        Train lastCart;
+        Train? lastCart;
         do
         {
             if (ShowProgress) { ShowGrid(); }
@@ -371,8 +371,8 @@ public class Day13 : IDay
 
     private int _width;
     private int _height;
-    private char[,] _grid;
+    private char[,] _grid = new char[0, 0];
-    private List<Train> _trains = new();
+    private readonly List<Train> _trains = [];
 
     private void Initialize(string[] inputs)
     {
@@ -387,8 +387,7 @@ public class Day13 : IDay
                 char cell = inputs[j][i];
                 if (cell == '^')
                 {
-                    _trains.Add(new Train
+                    _trains.Add(new Train {
-                    {
                         X = i,
                         Y = j,
                         Direction = TrainDirection.North,
@@ -398,8 +397,7 @@ public class Day13 : IDay
                 }
                 if (cell == 'v')
                 {
-                    _trains.Add(new Train
+                    _trains.Add(new Train {
-                    {
                         X = i,
                         Y = j,
                         Direction = TrainDirection.South,
@@ -409,8 +407,7 @@ public class Day13 : IDay
                 }
                 if (cell == '<')
                 {
-                    _trains.Add(new Train
+                    _trains.Add(new Train {
-                    {
                         X = i,
                         Y = j,
                         Direction = TrainDirection.West,
@@ -420,8 +417,7 @@ public class Day13 : IDay
                 }
                 if (cell == '>')
                 {
-                    _trains.Add(new Train
+                    _trains.Add(new Train {
-                    {
                         X = i,
                         Y = j,
                         Direction = TrainDirection.East,
@@ -434,9 +430,9 @@ public class Day13 : IDay
         }
     }
 
-    private Train SimulateForFirstCollision()
+    private Train? SimulateForFirstCollision()
     {
-        Train collidingTrain = null;
+        Train? collidingTrain = null;
         IEnumerable<Train> orderedTrains = _trains.OrderBy(t => t.X + (t.Y * _width));
         foreach (Train t in orderedTrains)
         {
@@ -447,13 +443,13 @@ public class Day13 : IDay
         return collidingTrain;
     }
 
-    private Train SimulateForLastCart()
+    private Train? SimulateForLastCart()
     {
         List<Train> orderedTrains = _trains.OrderBy(t => t.X + (t.Y * _width)).ToList();
         foreach (Train t in orderedTrains)
         {
             t.Simulate(_grid);
-            Train collidingTrain = _trains.FirstOrDefault(x => x.X == t.X && x.Y == t.Y && t != x);
+            Train? collidingTrain = _trains.FirstOrDefault(x => x.X == t.X && x.Y == t.Y && t != x);
             if (collidingTrain != null)
             {
                 _trains.Remove(t);
@@ -474,7 +470,7 @@ public class Day13 : IDay
         {
             for (int i = 0; i < _width; i++)
             {
-                Train t = _trains.FirstOrDefault(x => x.X == i && x.Y == j);
+                Train? t = _trains.FirstOrDefault(x => x.X == i && x.Y == j);
                 if (t != null)
                 {
                     if (t.Direction == TrainDirection.North)
@@ -502,5 +498,4 @@ public class Day13 : IDay
             Console.WriteLine();
         }
     }
-
 }

AdventOfCode2018/Day14.cs

@@ -62,7 +62,7 @@ public class Day14 : IDay
 {
     private long _numRecipes;
     private long _numRecipesAllocated;
-    private byte[] _recipes;
+    private byte[] _recipes = [];
     private long _idxA;
     private long _idxB;
     private long _searchSkip;

AdventOfCode2018/Day15.cs

@@ -377,18 +377,18 @@ public class Day15 : IDay
 {
     public enum EntityType { Elf, Goblin, }
 
-    public bool Show { get; set; } = false;
+    private bool Show { get; set; } = false;
 
     public class Entity
     {
-        public const int GoblinAttackPower = 3;
+        private const int GoblinAttackPower = 3;
         public static int ElfAttackPower { get; set; } = 3;
-        public const int InitialHealth = 200;
+        private const int InitialHealth = 200;
 
-        public EntityType Type { get; set; }
+        public EntityType Type { get; init; }
         public int X { get; set; }
         public int Y { get; set; }
-        public int Health { get; set; } = InitialHealth;
+        public int Health { get; private set; } = InitialHealth;
 
         public bool IsAlive()
         {
@@ -401,18 +401,17 @@ public class Day15 : IDay
                 (other.X + 1 == X && other.Y == Y) ||
                 (other.X - 1 == X && other.Y == Y) ||
                 (other.X == X && other.Y + 1 == Y) ||
-                (other.X == X && other.Y - 1 == Y) ||
+                (other.X == X && other.Y - 1 == Y)
-                false
             )
             {
                 return true;
             }
             return false;
         }
-            
+
         public void Attack(char[,] map, Entity other)
         {
-            if(Type == EntityType.Elf)
+            if (Type == EntityType.Elf)
             {
                 other.Health -= ElfAttackPower;
             }
@@ -435,28 +434,27 @@ public class Day15 : IDay
         }
     }
 
-    public class Target
+    private class Target
     {
-        public int X { get; set; }
+        public int X { get; init; }
-        public int Y { get; set; }
+        public int Y { get; init; }
         public int Distance { get; set; }
-        public int Priority { get; set; }
+        public int Priority { get; init; }
-        public Entity Entity { get; set; }
     }
 
     private int _width;
     private int _height;
-    private char[,] _map;
+    private char[,] _map = new char[0, 0];
-    private List<Entity> _entities;
+    private readonly List<Entity> _entities = [];
-    private BreadthFirstSearchGrid _search;
+    private BreadthFirstSearchGrid? _search;
     private int _rounds;
-        
+
     private void Init(string[] inputs)
     {
         _height = inputs.Length;
         _width = inputs.Max(input => input.Length);
         _map = new char[_width, _height];
-        _entities = new List<Entity>();
+        _entities.Clear();
         for (int j = 0; j < _height; j++)
         {
             for (int i = 0; i < _width; i++)
@@ -473,8 +471,7 @@ public class Day15 : IDay
                 }
                 else if (cell == 'E')
                 {
-                    _entities.Add(new Entity
+                    _entities.Add(new Entity {
-                    {
                         Type = EntityType.Elf,
                         X = i,
                         Y = j,
@@ -483,8 +480,7 @@ public class Day15 : IDay
                 }
                 else if (cell == 'G')
                 {
-                    _entities.Add(new Entity
+                    _entities.Add(new Entity {
-                    {
                         Type = EntityType.Goblin,
                         X = i,
                         Y = j,
@@ -505,7 +501,7 @@ public class Day15 : IDay
             .ThenBy(e => e.X);
     }
 
-    public IEnumerable<Entity> GetTargetEntities(Entity entity)
+    private IEnumerable<Entity> GetTargetEntities(Entity entity)
     {
         return _entities
             .Where(e => e.IsAlive() && e.Type != entity.Type)
@@ -513,30 +509,29 @@ public class Day15 : IDay
             .ThenBy(e => e.X);
     }
 
-    public Entity GetBestInRangeTarget(Entity entity, IEnumerable<Entity> targets)
+    private Entity? GetBestInRangeTarget(Entity entity, IEnumerable<Entity> targets)
     {
         return targets
-            .Where(e => entity.InRangeOf(e))
+            .Where(entity.InRangeOf)
             .OrderBy(e => e.Health)
             .ThenBy(e => e.Y)
             .ThenBy(e => e.X)
             .FirstOrDefault();
     }
 
-    private void AddTarget(List<Target> targets, int targetX, int targetY, int priority, Entity entity)
+    private void AddTarget(List<Target> targets, int targetX, int targetY, int priority)
     {
+        if (_search == null) { return;}
         if (targetX >= 0 && targetX < _width && targetY >= 0 && targetY < _height && _map[targetX, targetY] == '.')
         {
             int distance = _search.QueryDistance(targetX, targetY);
             if (distance >= 0)
             {
-                targets.Add(new Target
+                targets.Add(new Target {
-                {
                     X = targetX,
                     Y = targetY,
                     Distance = distance,
                     Priority = priority,
-                    Entity = entity,
                 });
             }
         }
@@ -544,6 +539,7 @@ public class Day15 : IDay
 
     private void RunBattle()
     {
+        if (_search == null) { return;}
         _rounds = 0;
         bool running = true;
         do
@@ -552,7 +548,7 @@ public class Day15 : IDay
             foreach (Entity entity in entities)
             {
                 if (entity.IsAlive() == false) { continue; }
-                IEnumerable<Entity> entitiesTargets = GetTargetEntities(entity);
+                IEnumerable<Entity> entitiesTargets = GetTargetEntities(entity).ToList();
                 if (entitiesTargets.Any() == false)
                 {
                     running = false;
@@ -560,7 +556,7 @@ public class Day15 : IDay
                 }
 
                 // Attack
-                Entity targetInRange = GetBestInRangeTarget(entity, entitiesTargets);
+                Entity? targetInRange = GetBestInRangeTarget(entity, entitiesTargets);
                 if (targetInRange != null)
                 {
                     entity.Attack(_map, targetInRange);
@@ -573,19 +569,18 @@ public class Day15 : IDay
                 int priority = 0;
                 foreach (Entity entityTarget in entitiesTargets)
                 {
-                    AddTarget(targets, entityTarget.X, entityTarget.Y - 1, priority++, entityTarget);
+                    AddTarget(targets, entityTarget.X, entityTarget.Y - 1, priority++);
-                    AddTarget(targets, entityTarget.X - 1, entityTarget.Y, priority++, entityTarget);
+                    AddTarget(targets, entityTarget.X - 1, entityTarget.Y, priority++);
-                    AddTarget(targets, entityTarget.X + 1, entityTarget.Y, priority++, entityTarget);
+                    AddTarget(targets, entityTarget.X + 1, entityTarget.Y, priority++);
-                    AddTarget(targets, entityTarget.X, entityTarget.Y + 1, priority++, entityTarget);
+                    AddTarget(targets, entityTarget.X, entityTarget.Y + 1, priority++);
                 }
-                Target bestTarget = targets.OrderBy(t => t.Distance).ThenBy(t => t.Priority).FirstOrDefault();
+                Target? bestTarget = targets.OrderBy(t => t.Distance).ThenBy(t => t.Priority).FirstOrDefault();
                 if (bestTarget != null)
                 {
                     _search.SearchCharGrid(_map, '.', bestTarget.X, bestTarget.Y);
                     targets.Clear();
-                    Target dirTarget;
 
-                    dirTarget = new Target { X = entity.X, Y = entity.Y - 1, Priority = 0, };
+                    Target dirTarget = new() { X = entity.X, Y = entity.Y - 1, Priority = 0, };
                     dirTarget.Distance = _search.QueryDistance(dirTarget.X, dirTarget.Y);
                     if (dirTarget.Distance >= 0) targets.Add(dirTarget);
 
@@ -601,7 +596,7 @@ public class Day15 : IDay
                     dirTarget.Distance = _search.QueryDistance(dirTarget.X, dirTarget.Y);
                     if (dirTarget.Distance >= 0) targets.Add(dirTarget);
 
-                    Target finalTarget = targets
+                    Target? finalTarget = targets
                         .OrderBy(t => t.Distance)
                         .ThenBy(t => t.Priority)
                         .FirstOrDefault();
@@ -609,21 +604,21 @@ public class Day15 : IDay
                     {
                         throw new Exception("No possible direction");
                     }
-                        
+
                     entity.MoveTo(_map, finalTarget.X, finalTarget.Y);
 
                     // Attack
-                    Entity targetInRangeAfterMove = GetBestInRangeTarget(entity, entitiesTargets);
+                    Entity? targetInRangeAfterMove = GetBestInRangeTarget(entity, entitiesTargets);
                     if (targetInRangeAfterMove != null)
                     {
                         entity.Attack(_map, targetInRangeAfterMove);
                     }
                 }
             }
-            if(running == false) { break; }
+            if (running == false) { break; }
             _rounds++;
             if (Show) { PrintBattlefield(); }
-        } while (running);
+        } while (true);
         if (Show) { PrintBattlefield(); }
     }
 
@@ -637,7 +632,8 @@ public class Day15 : IDay
             {
                 Console.Write(_map[i, j]);
             }
-            IEnumerable<Entity> entitiesOnLine = _entities.Where(e => e.IsAlive() && e.Y == j).OrderBy(e => e.X);
+            int j1 = j;
+            IEnumerable<Entity> entitiesOnLine = _entities.Where(e => e.IsAlive() && e.Y == j1).OrderBy(e => e.X);
             foreach (Entity entity in entitiesOnLine)
             {
                 Console.Write(" {0}({1})", (entity.Type == EntityType.Elf) ? 'E' : 'G', entity.Health);
@@ -683,16 +679,15 @@ public class Day15 : IDay
         private class BFSCell
         {
             public bool Visited { get; set; }
-            public BFSCell CameFrom { get; set; }
             public int Distance { get; set; } = -1;
-            public int X { get; set; }
+            public int X { get; init; }
-            public int Y { get; set; }
+            public int Y { get; init; }
         }
 
         private readonly BFSCell[,] _grid;
         private readonly int _width;
         private readonly int _height;
- 
+
         public BreadthFirstSearchGrid(int width, int height)
         {
             _grid = new BFSCell[width, height];
@@ -707,24 +702,23 @@ public class Day15 : IDay
             }
         }
 
-        public void Reset()
+        private void Reset()
         {
-            for(int j =0;j< _height; j++)
+            for (int j = 0; j < _height; j++)
             {
-                for(int i = 0; i < _width; i++)
+                for (int i = 0; i < _width; i++)
                 {
                     BFSCell cell = _grid[i, j];
                     cell.Visited = false;
-                    cell.CameFrom = null;
                     cell.Distance = -1;
                 }
             }
         }
 
-        private void ProcessCell(char[,] grid, char empty, Queue<BFSCell> frontier, BFSCell current, int nextX, int nextY)
+        private void ProcessCell(char[,] grid, char empty, Queue<BFSCell> frontier, BFSCell? current, int nextX, int nextY)
         {
             if (nextX < 0 || nextX >= _width || nextY < 0 || nextY >= _height) { return; }
-            if (grid[nextX, nextY] == empty || current== null)
+            if (grid[nextX, nextY] == empty || current == null)
             {
                 BFSCell cell = _grid[nextX, nextY];
                 if (cell.Visited == false)
@@ -732,7 +726,6 @@ public class Day15 : IDay
                     frontier.Enqueue(cell);
                     cell.Visited = true;
                     cell.Distance = (current?.Distance ?? -1) + 1;
-                    cell.CameFrom = current;
                 }
             }
         }

AdventOfCode2018/Day16.cs

@@ -87,8 +87,8 @@ public class Day16 : IDay
         int count = 0;
         int i = 0;
         bool end = false;
-        int[] beforeRegisters = null;
+        int[]? beforeRegisters = null;
-        int[] instruction = null;
+        int[]? instruction = null;
         const string beforeKeyword = "Before: [";
         const string afterKeyword = "After:  [";
         while (inputs.Length > i)
@@ -160,17 +160,11 @@ public class Day16 : IDay
 
         private readonly List<ChronoInstruction> _instructions;
 
-        private class ChronoInstruction
+        private class ChronoInstruction(string opName, Action<int, int, int> opFunc)
         {
             public int OpCode { get; set; } = -1;
-            public string OpName { get; }
+            public string OpName { get; } = opName;
-            public Action<int, int, int> OpFunc { get; }
+            public Action<int, int, int> OpFunc { get; } = opFunc;
-
-            public ChronoInstruction(string opName, Action<int, int, int> opFunc)
-            {
-                OpName = opName;
-                OpFunc = opFunc;
-            }
 
             public Dictionary<int, int> OpCodeHistogram { get; } = new();
 
@@ -191,7 +185,7 @@ public class Day16 : IDay
         public ChronoMachine()
         {
             _registers = new int[4];
-            _instructions = new List<ChronoInstruction> {
+            _instructions = [
                 new("addr", Op_AddR),
                 new("addi", Op_AddI),
                 new("mulr", Op_MulR),
@@ -208,7 +202,7 @@ public class Day16 : IDay
                 new("eqir", Op_EqIR),
                 new("eqri", Op_EqRI),
                 new("eqrr", Op_EqRR),
-            };
+            ];
         }
 
         public void ResetRegisters()
@@ -341,7 +335,7 @@ public class Day16 : IDay
 
         public void InitOpCodes(bool debug = false)
         {
-            if(debug)
+            if (debug)
             {
                 foreach (ChronoInstruction instruction in _instructions)
                 {
@@ -374,7 +368,7 @@ public class Day16 : IDay
 
                     instruction.OpCode = opCode;
                     _dictInstructions.Add(opCode, instruction);
-                    if(debug) { Console.WriteLine($"{instruction.OpName}: {instruction.OpCode}"); }
+                    if (debug) { Console.WriteLine($"{instruction.OpName}: {instruction.OpCode}"); }
                 }
             }
         }

AdventOfCode2018/Day23.cs

@@ -68,8 +68,8 @@ public class Day23 : IDay
     public string ResolvePart1(string[] inputs)
     {
         List<NanoBot> nanoBots = NanoBot.ListFromStrings(inputs);
-        NanoBot bestNanoBot = nanoBots.OrderBy(nanoBot => nanoBot.Range).LastOrDefault();
+        NanoBot? bestNanoBot = nanoBots.OrderBy(nanoBot => nanoBot.Range).LastOrDefault();
-        int countInRange = nanoBots.Where(nanoBot => bestNanoBot.InRange(nanoBot)).Count();
+        int countInRange = nanoBots.Count(nanoBot => bestNanoBot?.InRange(nanoBot) == true);
         return countInRange.ToString();
     }
 
@@ -82,7 +82,7 @@ public class Day23 : IDay
         long minX = long.MaxValue;
         long minY = long.MaxValue;
         long minZ = long.MaxValue;
-        foreach(NanoBot nanoBot in nanoBots)
+        foreach (NanoBot nanoBot in nanoBots)
         {
             if (nanoBot.X < minX) { minX = nanoBot.X; }
             if (nanoBot.X > maxX) { maxX = nanoBot.X; }
@@ -95,7 +95,7 @@ public class Day23 : IDay
         long sizeY = maxY - minY;
         long sizeZ = maxZ - minZ;
         long scale = Math.Min(sizeX, Math.Min(sizeY, sizeZ));
-            
+
         do
         {
             scale /= 2;
@@ -112,11 +112,11 @@ public class Day23 : IDay
                     for (long i = minX; i <= maxX; i += scale)
                     {
                         int count = 0;
-                        foreach(NanoBot nanoBot in nanoBots)
+                        foreach (NanoBot nanoBot in nanoBots)
                         {
                             if (nanoBot.InRange(i, j, k, scale)) { count++; }
                         }
-                        if(count> bestCount)
+                        if (count > bestCount)
                         {
                             bestX = i;
                             bestY = j;
@@ -134,7 +134,7 @@ public class Day23 : IDay
             minZ = bestZ - scale;
             maxZ = bestZ + scale;
 
-            if(scale == 1)
+            if (scale == 1)
             {
                 long distance = bestX + bestY + bestZ;
                 return distance.ToString();
@@ -145,14 +145,14 @@ public class Day23 : IDay
 
     public class NanoBot
     {
-        public long X { get; set; }
+        public long X { get; private init; }
-        public long Y { get; set; }
+        public long Y { get; private init; }
-        public long Z { get; set; }
+        public long Z { get; private init; }
-        public long Range { get; set; }
+        public long Range { get; private init; }
 
-        public static NanoBot FromString(string strInput)
+        private static NanoBot? FromString(string strInput)
         {
-            string[] parts = strInput.Split(new[] { "pos=<", ",", ">, r=", }, StringSplitOptions.RemoveEmptyEntries);
+            string[] parts = strInput.Split(["pos=<", ",", ">, r="], StringSplitOptions.RemoveEmptyEntries);
             if (parts.Length != 4) { return null; }
             NanoBot nanoBot = new() {
                 X = Convert.ToInt64(parts[0]),
@@ -166,18 +166,18 @@ public class Day23 : IDay
         public static List<NanoBot> ListFromStrings(string[] inputs)
         {
             List<NanoBot> nanoBots = inputs
-                .Select(strInput => FromString(strInput))
+                .Select(FromString)
-                .Where(nanoBot => nanoBot != null)
+                .OfType<NanoBot>()
                 .ToList();
             return nanoBots;
         }
 
-        public long ManhattanDistance(NanoBot other)
+        private long ManhattanDistance(NanoBot other)
         {
             return ManhattanDistance(other.X, other.Y, other.Z);
         }
 
-        public long ManhattanDistance(long x, long y, long z)
+        private long ManhattanDistance(long x, long y, long z)
         {
             long distance = Math.Abs(X - x) + Math.Abs(Y - y) + Math.Abs(Z - z);
             return distance;

AdventOfCode2020.Tests/AdventOfCode2020.Tests.csproj

@@ -1,24 +1,26 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <PropertyGroup>
+    <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
+        <ImplicitUsings>enable</ImplicitUsings>
-    <RootNamespace>AdventOfCode2020.Tests</RootNamespace>
+        <Nullable>enable</Nullable>
+        <RootNamespace>AdventOfCode2020.Tests</RootNamespace>
 
-    <IsPackable>false</IsPackable>
+        <IsPackable>false</IsPackable>
-  </PropertyGroup>
+        <IsTestProject>true</IsTestProject>
+    </PropertyGroup>
 
-  <ItemGroup>
+    <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0"/>
-    <PackageReference Include="xunit" Version="2.6.3" />
+        <PackageReference Include="xunit" Version="2.6.3"/>
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.5">
+        <PackageReference Include="xunit.runner.visualstudio" Version="2.5.5">
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-      <PrivateAssets>all</PrivateAssets>
+            <PrivateAssets>all</PrivateAssets>
-    </PackageReference>
+        </PackageReference>
-  </ItemGroup>
+    </ItemGroup>
 
-  <ItemGroup>
+    <ItemGroup>
-    <ProjectReference Include="..\AdventOfCode2020\AdventOfCode2020.csproj" />
+        <ProjectReference Include="..\AdventOfCode2020\AdventOfCode2020.csproj"/>
-  </ItemGroup>
+    </ItemGroup>
 
 </Project>

AdventOfCode2020.Tests/Day01_Tests.cs

@@ -7,16 +7,16 @@ public class Day01_Tests
     [Fact]
     public void ResolvePart1__Example()
     {
-        var day = new Day01();
+        Day01 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "1721",
             "979",
             "366",
             "299",
             "675",
             "1456",
-        });
+        ]);
 
         Assert.Equal("514579", result);
     }
@@ -28,16 +28,16 @@ public class Day01_Tests
     [Fact]
     public void ResolvePart2__Example()
     {
-        var day = new Day01();
+        Day01 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "1721",
             "979",
             "366",
             "299",
             "675",
             "1456",
-        });
+        ]);
 
         Assert.Equal("241861950", result);
     }

AdventOfCode2020.Tests/Day02_Tests.cs

@@ -7,13 +7,13 @@ public class Day02_Tests
     [Fact]
     public void ResolvePart1__Example()
     {
-        var day = new Day02();
+        Day02 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "1-3 a: abcde",
             "1-3 b: cdefg",
             "2-9 c: ccccccccc",
-        });
+        ]);
 
         Assert.Equal("2", result);
     }
@@ -25,13 +25,13 @@ public class Day02_Tests
     [Fact]
     public void ResolvePart2__Example()
     {
-        var day = new Day02();
+        Day02 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "1-3 a: abcde",
             "1-3 b: cdefg",
             "2-9 c: ccccccccc",
-        });
+        ]);
 
         Assert.Equal("1", result);
     }

AdventOfCode2020.Tests/Day03_Tests.cs

@@ -5,9 +5,9 @@ public class Day03_Tests
     [Fact]
     public void ResolvePart1__Example()
     {
-        var day = new Day03();
+        Day03 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "..##.......",
             "#...#...#..",
             ".#....#..#.",
@@ -19,7 +19,7 @@ public class Day03_Tests
             "#.##...#...",
             "#...##....#",
             ".#..#...#.#",
-        });
+        ]);
 
         Assert.Equal("7", result);
     }
@@ -27,9 +27,9 @@ public class Day03_Tests
     [Fact]
     public void ResolvePart2__Example()
     {
-        var day = new Day03();
+        Day03 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "..##.......",
             "#...#...#..",
             ".#....#..#.",
@@ -41,7 +41,7 @@ public class Day03_Tests
             "#.##...#...",
             "#...##....#",
             ".#..#...#.#",
-        });
+        ]);
 
         Assert.Equal("336", result);
     }

AdventOfCode2020.Tests/Day04_Tests.cs

@@ -5,9 +5,9 @@ public class Day04_Tests
     [Fact]
     public void ResolvePart1__Example()
     {
-        var day = new Day04();
+        Day04 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "ecl:gry pid:860033327 eyr:2020 hcl:#fffffd",
             "byr:1937 iyr:2017 cid:147 hgt:183cm",
             "",
@@ -21,7 +21,7 @@ public class Day04_Tests
             "",
             "hcl:#cfa07d eyr:2025 pid:166559648",
             "iyr:2011 ecl:brn hgt:59in",
-        });
+        ]);
 
         Assert.Equal("2", result);
     }
@@ -29,9 +29,9 @@ public class Day04_Tests
     [Fact]
     public void ResolvePart2__ExampleInvalid()
     {
-        var day = new Day04();
+        Day04 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "eyr:1972 cid:100",
             "hcl:#18171d ecl:amb hgt:170 pid:186cm iyr:2018 byr:1926",
             "",
@@ -45,7 +45,7 @@ public class Day04_Tests
             "hgt:59cm ecl:zzz",
             "eyr:2038 hcl:74454a iyr:2023",
             "pid:3556412378 byr:2007",
-        });
+        ]);
 
         Assert.Equal("0", result);
     }
@@ -53,9 +53,9 @@ public class Day04_Tests
     [Fact]
     public void ResolvePart2__ExampleValid()
     {
-        var day = new Day04();
+        Day04 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "pid:087499704 hgt:74in ecl:grn iyr:2012 eyr:2030 byr:1980",
             "hcl:#623a2f",
             "",
@@ -68,7 +68,7 @@ public class Day04_Tests
             "eyr:2022",
             "",
             "iyr:2010 hgt:158cm hcl:#b6652a ecl:blu byr:1944 eyr:2021 pid:093154719",
-        });
+        ]);
 
         Assert.Equal("4", result);
     }

AdventOfCode2020.Tests/Day05_Tests.cs

@@ -5,11 +5,11 @@ public class Day05_Tests
     [Fact]
     public void ResolvePart1__Example1()
     {
-        var day = new Day05();
+        Day05 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "FBFBBFFRLR",
-        });
+        ]);
 
         Assert.Equal("357", result);
     }
@@ -17,11 +17,11 @@ public class Day05_Tests
     [Fact]
     public void ResolvePart1__Example2()
     {
-        var day = new Day05();
+        Day05 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "BFFFBBFRRR",
-        });
+        ]);
 
         Assert.Equal("567", result);
     }
@@ -29,11 +29,11 @@ public class Day05_Tests
     [Fact]
     public void ResolvePart1__Example3()
     {
-        var day = new Day05();
+        Day05 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "FFFBBBFRRR",
-        });
+        ]);
 
         Assert.Equal("119", result);
     }
@@ -41,11 +41,11 @@ public class Day05_Tests
     [Fact]
     public void ResolvePart1__Example4()
     {
-        var day = new Day05();
+        Day05 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "BBFFBBFRLL",
-        });
+        ]);
 
         Assert.Equal("820", result);
     }

AdventOfCode2020.Tests/Day06_Tests.cs

@@ -5,9 +5,9 @@ public class Day06_Tests
     [Fact]
     public void ResolvePart1__Example()
     {
-        var day = new Day06();
+        Day06 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "abc",
             "",
             "a",
@@ -23,7 +23,7 @@ public class Day06_Tests
             "a",
             "",
             "b",
-        });
+        ]);
 
         Assert.Equal("11", result);
     }
@@ -31,9 +31,9 @@ public class Day06_Tests
     [Fact]
     public void ResolvePart2__Example()
     {
-        var day = new Day06();
+        Day06 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "abc",
             "",
             "a",
@@ -49,7 +49,7 @@ public class Day06_Tests
             "a",
             "",
             "b",
-        });
+        ]);
 
         Assert.Equal("6", result);
     }

AdventOfCode2020.Tests/Day07_Tests.cs

@@ -5,9 +5,9 @@ public class Day07_Tests
     [Fact]
     public void ResolvePart1__Example()
     {
-        var day = new Day07();
+        Day07 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "light red bags contain 1 bright white bag, 2 muted yellow bags.",
             "dark orange bags contain 3 bright white bags, 4 muted yellow bags.",
             "bright white bags contain 1 shiny gold bag.",
@@ -17,7 +17,7 @@ public class Day07_Tests
             "vibrant plum bags contain 5 faded blue bags, 6 dotted black bags.",
             "faded blue bags contain no other bags.",
             "dotted black bags contain no other bags.",
-        });
+        ]);
 
         Assert.Equal("4", result);
     }
@@ -25,9 +25,9 @@ public class Day07_Tests
     [Fact]
     public void ResolvePart2__Example()
     {
-        var day = new Day07();
+        Day07 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "shiny gold bags contain 2 dark red bags.",
             "dark red bags contain 2 dark orange bags.",
             "dark orange bags contain 2 dark yellow bags.",
@@ -35,7 +35,7 @@ public class Day07_Tests
             "dark green bags contain 2 dark blue bags.",
             "dark blue bags contain 2 dark violet bags.",
             "dark violet bags contain no other bags.",
-        });
+        ]);
 
         Assert.Equal("126", result);
     }

AdventOfCode2020.Tests/Day08_Tests.cs

@@ -5,9 +5,9 @@ public class Day08_Tests
     [Fact]
     public void ResolvePart1__Example()
     {
-        var day = new Day08();
+        Day08 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "nop +0",
             "acc +1",
             "jmp +4",
@@ -17,7 +17,7 @@ public class Day08_Tests
             "acc +1",
             "jmp -4",
             "acc +6",
-        });
+        ]);
 
         Assert.Equal("5", result);
     }
@@ -25,9 +25,9 @@ public class Day08_Tests
     [Fact]
     public void ResolvePart2__Example()
     {
-        var day = new Day08();
+        Day08 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "nop +0",
             "acc +1",
             "jmp +4",
@@ -37,7 +37,7 @@ public class Day08_Tests
             "acc +1",
             "jmp -4",
             "acc +6",
-        });
+        ]);
 
         Assert.Equal("8", result);
     }

AdventOfCode2020.Tests/Day09_Tests.cs

@@ -5,9 +5,9 @@ public class Day09_Tests
     [Fact]
     public void ResolvePart1__Example()
     {
-        var day = new Day09();
+        Day09 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "35",
             "20",
             "15",
@@ -28,7 +28,7 @@ public class Day09_Tests
             "277",
             "309",
             "576",
-        });
+        ]);
 
         Assert.Equal("127", result);
     }
@@ -36,9 +36,9 @@ public class Day09_Tests
     [Fact]
     public void ResolvePart2__Example()
     {
-        var day = new Day09();
+        Day09 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "35",
             "20",
             "15",
@@ -59,7 +59,7 @@ public class Day09_Tests
             "277",
             "309",
             "576",
-        });
+        ]);
 
         Assert.Equal("62", result);
     }

AdventOfCode2020/AdventOfCode2020.csproj

@@ -1,20 +1,21 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <PropertyGroup>
+    <PropertyGroup>
-    <OutputType>Exe</OutputType>
+        <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
+        <ImplicitUsings>enable</ImplicitUsings>
-    <RootNamespace>AdventOfCode2020</RootNamespace>
+        <Nullable>enable</Nullable>
-  </PropertyGroup>
+        <RootNamespace>AdventOfCode2020</RootNamespace>
+    </PropertyGroup>
 
-  <ItemGroup>
+    <ItemGroup>
-    <None Update="inputs\*">
+        <None Update="inputs\*">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+            <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </None>
+        </None>
-  </ItemGroup>
+    </ItemGroup>
 
-  <ItemGroup>
+    <ItemGroup>
-    <ProjectReference Include="..\AdventOfCode.Common\AdventOfCode.Common.csproj" />
+        <ProjectReference Include="..\AdventOfCode.Common\AdventOfCode.Common.csproj"/>
-  </ItemGroup>
+    </ItemGroup>
 
 </Project>

AdventOfCode2020/Day03.cs

@@ -112,5 +112,4 @@ public class Day03 : IDay
         }
         return treeCnt;
     }
-
 }

AdventOfCode2020/Day04.cs

@@ -118,7 +118,7 @@ iyr:2010 hgt:158cm hcl:#b6652a ecl:blu byr:1944 eyr:2021 pid:093154719
 
 Count the number of valid passports - those that have all required fields and valid values. Continue to treat cid as optional. In your batch file, how many passports are valid?
 
- 
+
 */
 
 public class Day04 : IDay
@@ -127,7 +127,7 @@ public class Day04 : IDay
     {
         List<Dictionary<string, string>> passports = Passports_Parse(inputs);
         int cnt = 0;
-        List<string> neededFields = new() {
+        List<string> neededFields = [
             "byr", // Birth Year
             "iyr", // Issue Year
             "eyr", // Expiration Year
@@ -135,7 +135,7 @@ public class Day04 : IDay
             "hcl", // Hair Color
             "ecl", // Eye Color
             "pid", // Passport ID
-        };
+        ];
 
         foreach (Dictionary<string, string> passport in passports)
         {
@@ -167,7 +167,7 @@ public class Day04 : IDay
 
     private List<Dictionary<string, string>> Passports_Parse(string[] inputs)
     {
-        List<Dictionary<string, string>> passports = new();
+        List<Dictionary<string, string>> passports = [];
         Dictionary<string, string> passport = new();
         foreach (string input in inputs)
         {
@@ -257,5 +257,4 @@ public class Day04 : IDay
         if (input.All(char.IsNumber) == false) { return null; }
         return Convert.ToInt32(input);
     }
-
 }

AdventOfCode2020/Day05.cs

@@ -64,7 +64,7 @@ public class Day05 : IDay
         int maxSerialNumber = 0;
         foreach (string input in inputs)
         {
-            Seat seat = Seat_Parse(input);
+            Seat? seat = Seat_Parse(input);
             if (seat == null) { continue; }
             int newSerialNumber = seat.GetSerialNumber();
             if (newSerialNumber > maxSerialNumber) { maxSerialNumber = newSerialNumber; }
@@ -83,7 +83,7 @@ public class Day05 : IDay
         }
         foreach (string input in inputs)
         {
-            Seat seat = Seat_Parse(input);
+            Seat? seat = Seat_Parse(input);
             if (seat == null) { continue; }
 
             seats[seat.Column][seat.Row] = 'X';
@@ -166,11 +166,11 @@ public class Day05 : IDay
         }
     }
 
-    private Seat Seat_Parse(string input)
+    private Seat? Seat_Parse(string input)
     {
         if (input.Length != 10 ||
-            input.All(c => c == 'F' || c == 'B' || c == 'L' || c == 'R') == false ||
+            input.All(c => c == 'F' || c == 'B' || c == 'L' || c == 'R') == false
-            false)
+           )
         {
             return null;
         }

AdventOfCode2020/Day06.cs

@@ -67,10 +67,7 @@ public class Day06 : IDay
 
             foreach (char c in input)
             {
-                if (groupMap.ContainsKey(c) == false)
+                groupMap.TryAdd(c, true);
-                {
-                    groupMap.Add(c, true);
-                }
             }
         }
         if (groupMap.Count > 0)
@@ -78,7 +75,7 @@ public class Day06 : IDay
             groupMaps.Add(groupMap);
         }
 
-        int total = groupMaps.Sum(groupMap => groupMap.Count);
+        int total = groupMaps.Sum(dict => dict.Count);
         return total.ToString();
 
     }
@@ -101,13 +98,9 @@ public class Day06 : IDay
             groupCount++;
             foreach (char c in input)
             {
-                if (groupMap.ContainsKey(c) == false)
+                if (groupMap.TryAdd(c, 1) == false)
                 {
-                    groupMap.Add(c, 1);
+                    groupMap[c] += 1;
-                }
-                else
-                {
-                    groupMap[c] = groupMap[c] + 1;
                 }
             }
         }

AdventOfCode2020/Day07.cs

@@ -72,15 +72,15 @@ public class Day07 : IDay
     {
         string myBagColor = "shiny gold";
 
-        List<BaggageRule> rules = new();
+        List<BaggageRule> rules = [];
         foreach (string input in inputs)
         {
             BaggageRule rule = BaggageRule_Parse(input);
             rules.Add(rule);
         }
 
-        List<string> bagColorsToCheck = new() { myBagColor };
+        List<string> bagColorsToCheck = [myBagColor];
-        List<string> bagColorsChecked = new() { myBagColor };
+        List<string> bagColorsChecked = [myBagColor];
         int cntBagColors = 0;
         while (bagColorsToCheck.Count > 0)
         {
@@ -108,7 +108,7 @@ public class Day07 : IDay
     {
         string myBagColor = "shiny gold";
 
-        List<BaggageRule> rules = new();
+        List<BaggageRule> rules = [];
         foreach (string input in inputs)
         {
             BaggageRule rule = BaggageRule_Parse(input);
@@ -116,31 +116,30 @@ public class Day07 : IDay
         }
         Dictionary<string, BaggageRule> dictRules = rules.ToDictionary(x => x.BagColor);
 
-        int cnt = BaggageRule_CountChilds(myBagColor, dictRules);
+        int cnt = BaggageRule_CountChildren(myBagColor, dictRules);
 
         return cnt.ToString();
     }
 
-    public class BaggageContainRule
+    private class BaggageContainRule
     {
-        public string BagColor { get; set; }
+        public string BagColor { get; set; } = string.Empty;
-        public int Count { get; set; }
+        public int Count { get; init; }
     }
 
-    public class BaggageRule
+    private class BaggageRule
     {
-        public string BagColor { get; set; }
+        public string BagColor { get; set; } = string.Empty;
 
-        public List<BaggageContainRule> Contain { get; set; }
+        public List<BaggageContainRule> Contain { get; } = [];
     }
 
-    public BaggageRule BaggageRule_Parse(string input)
+    private BaggageRule BaggageRule_Parse(string input)
     {
         string[] words = input.Split(' ');
         string status = "Parse Color 1";
         BaggageRule rule = new();
-        rule.Contain = new List<BaggageContainRule>();
+        BaggageContainRule? containRule = null;
-        BaggageContainRule containRule = null;
         string color1 = string.Empty;
 
         foreach (string word in words)
@@ -164,9 +163,14 @@ public class Day07 : IDay
                     status = "Parse Contain count";
                     break;
                 case "Parse Contain count":
-                    if (word == "no") { status = "End"; break; }
+                    if (word == "no")
-                    containRule = new BaggageContainRule();
+                    {
-                    containRule.Count = Convert.ToInt32(word);
+                        status = "End";
+                        break;
+                    }
+                    containRule = new BaggageContainRule {
+                        Count = Convert.ToInt32(word),
+                    };
                     status = "Parse Contain color 1";
                     break;
                 case "Parse Contain color 1":
@@ -174,12 +178,17 @@ public class Day07 : IDay
                     status = "Parse Contain color 2";
                     break;
                 case "Parse Contain color 2":
+                    if(containRule == null) { break; } 
                     containRule.BagColor = string.Concat(color1, " ", word);
                     rule.Contain.Add(containRule);
                     status = "Parse Contain continue";
                     break;
                 case "Parse Contain continue":
-                    if (word == "bag," || word == "bags,") { status = "Parse Contain count"; break; }
+                    if (word == "bag," || word == "bags,")
+                    {
+                        status = "Parse Contain count";
+                        break;
+                    }
                     status = "End";
                     break;
                 case "End":
@@ -189,13 +198,13 @@ public class Day07 : IDay
         return rule;
     }
 
-    public int BaggageRule_CountChilds(string color, Dictionary<string, BaggageRule> dictRules)
+    private int BaggageRule_CountChildren(string color, Dictionary<string, BaggageRule> dictRules)
     {
         int cnt = 0;
         BaggageRule rule = dictRules[color];
         foreach (BaggageContainRule containRule in rule.Contain)
         {
-            cnt += (BaggageRule_CountChilds(containRule.BagColor, dictRules) + 1) * containRule.Count;
+            cnt += (BaggageRule_CountChildren(containRule.BagColor, dictRules) + 1) * containRule.Count;
         }
         return cnt;
     }

AdventOfCode2020/Day08.cs

@@ -124,14 +124,14 @@ public class Day08 : IDay
         return vm.Accumulator.ToString();
     }
 
-    public enum OpCode
+    private enum OpCode
     {
         Acc,
         Jmp,
         Nop,
     }
 
-    public class Instruction
+    private class Instruction
     {
         public OpCode OpCode { get; set; }
         public int Value { get; set; }
@@ -154,14 +154,9 @@ public class Day08 : IDay
                 OpCode = OpCode.Nop;
             }
 
-            if (parts[1].StartsWith("+"))
+            Value = Convert.ToInt32(parts[1].StartsWith("+") 
-            {
+                ? parts[1].Substring(1) 
-                Value = Convert.ToInt32(parts[1].Substring(1));
+                : parts[1]);
-            }
-            else
-            {
-                Value = Convert.ToInt32(parts[1]);
-            }
             Executed = false;
         }
     }
@@ -176,7 +171,7 @@ public class Day08 : IDay
 
         public VM(string[] inputs)
         {
-            Instructions = new List<Instruction>();
+            Instructions = [];
             foreach (string input in inputs)
             {
                 Instructions.Add(new Instruction(input));

AdventOfCode2020/Day09.cs

@@ -163,5 +163,4 @@ public class Day09 : IDay
 
         return firstInvalid;
     }
-
 }

AdventOfCode2023.Tests/AdventOfCode2023.Tests.csproj

@@ -1,17 +1,18 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
-        <RootNamespace>AdventOfCode2023.Tests</RootNamespace>
         <Nullable>enable</Nullable>
+        <RootNamespace>AdventOfCode2023.Tests</RootNamespace>
 
         <IsPackable>false</IsPackable>
+        <IsTestProject>true</IsTestProject>
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0"/>
-        <PackageReference Include="xunit" Version="2.6.3" />
+        <PackageReference Include="xunit" Version="2.6.3"/>
         <PackageReference Include="xunit.runner.visualstudio" Version="2.5.5">
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
             <PrivateAssets>all</PrivateAssets>
@@ -19,7 +20,7 @@
     </ItemGroup>
 
     <ItemGroup>
-      <ProjectReference Include="..\AdventOfCode2023\AdventOfCode2023.csproj" />
+        <ProjectReference Include="..\AdventOfCode2023\AdventOfCode2023.csproj"/>
     </ItemGroup>
 
 </Project>

AdventOfCode2023.Tests/Day01_Tests.cs

@@ -5,24 +5,24 @@ public class Day01_Tests
     [Fact]
     public void ResolvePart1__Example()
     {
-        var day = new Day01();
+        Day01 day = new();
 
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "1abc2",
             "pqr3stu8vwx",
             "a1b2c3d4e5f",
             "treb7uchet",
-        });
+        ]);
 
         Assert.Equal("142", result);
     }
-    
+
     [Fact]
     public void ResolvePart2__Example()
     {
-        var day = new Day01();
+        Day01 day = new();
 
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "two1nine",
             "eightwothree",
             "abcone2threexyz",
@@ -30,7 +30,7 @@ public class Day01_Tests
             "4nineeightseven2",
             "zoneight234",
             "7pqrstsixteen",
-        });
+        ]);
 
         Assert.Equal("281", result);
     }

AdventOfCode2023.Tests/Day02_Tests.cs

@@ -18,7 +18,7 @@ public class Day02_Tests
         Assert.Equal(0, game.Sets[2].Blue);
         Assert.Equal(2, game.Sets[2].Green);
     }
-    
+
     [Fact]
     public void Game_FromString__ValidExample2()
     {
@@ -35,35 +35,35 @@ public class Day02_Tests
         Assert.Equal(0, game.Sets[2].Blue);
         Assert.Equal(5, game.Sets[2].Green);
     }
-    
+
     [Fact]
     public void ResolvePart1__Example()
     {
         Day02 day = new();
-        
+
-        string result = day.ResolvePart1(new[] {
+        string result = day.ResolvePart1([
             "Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green",
             "Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue",
             "Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red",
             "Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red",
             "Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green",
-        });
+        ]);
 
         Assert.Equal("8", result);
     }
-    
+
     [Fact]
     public void ResolvePart2__Example()
     {
         Day02 day = new();
-        
+
-        string result = day.ResolvePart2(new[] {
+        string result = day.ResolvePart2([
             "Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green",
             "Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue",
             "Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red",
             "Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red",
             "Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green",
-        });
+        ]);
 
         Assert.Equal("2286", result);
     }

AdventOfCode2023.Tests/Day03_Tests.cs

@@ -5,26 +5,26 @@ public class Day03_Tests
     [Fact]
     public void SearchNextSchemaNumber__NoNumbers__Null()
     {
-        string[] inputs = new[] {
+        string[] inputs = [
             "..........",
             "..........",
             "..........",
-        };
+        ];
         Day03.SchemaNumber? number = Day03.SearchNextSchemaNumber(inputs, 0, 0);
-        
+
         Assert.Null(number);
     }
 
     [Fact]
     public void SearchNextSchemaNumber__OneNumber__Valid()
     {
-        string[] inputs = new[] {
+        string[] inputs = [
             "..........",
             "....420...",
             "..........",
-        };
+        ];
         Day03.SchemaNumber? number = Day03.SearchNextSchemaNumber(inputs, 0, 0);
-        
+
         Assert.NotNull(number);
         Assert.Equal(1, number.Value.Row);
         Assert.Equal(4, number.Value.Column);
@@ -35,13 +35,13 @@ public class Day03_Tests
     [Fact]
     public void SearchNextSchemaNumber__TwoNumbersSkipFirst__ValidSecond()
     {
-        string[] inputs = new[] {
+        string[] inputs = [
             "69........",
             "....420...",
             "..........",
-        };
+        ];
         Day03.SchemaNumber? number = Day03.SearchNextSchemaNumber(inputs, 0, 4);
-        
+
         Assert.NotNull(number);
         Assert.Equal(1, number.Value.Row);
         Assert.Equal(4, number.Value.Column);
@@ -49,7 +49,7 @@ public class Day03_Tests
         Assert.Equal(420, number.Value.Value);
     }
 
-    private string[] _example = new[] {
+    private string[] _example = [
         "467..114..",
         "...*......",
         "..35..633.",
@@ -60,24 +60,24 @@ public class Day03_Tests
         "......755.",
         "...$.*....",
         ".664.598..",
-    };
+    ];
-    
+
     [Fact]
     public void ResolvePart1__Example()
     {
         Day03 day = new();
-        
+
         string result = day.ResolvePart1(_example);
 
         Assert.Equal("4361", result);
     }
-    
+
-    
+
     [Fact]
     public void ResolvePart2__Example()
     {
         Day03 day = new();
-        
+
         string result = day.ResolvePart2(_example);
 
         Assert.Equal("467835", result);

AdventOfCode2023.Tests/Day04_Tests.cs

@@ -2,20 +2,20 @@ namespace AdventOfCode2023.Tests;
 
 public class Day04_Tests
 {
-    private readonly string[] _example = {
+    private readonly string[] _example = [
         "Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53",
         "Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19",
         "Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1",
         "Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83",
         "Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36",
         "Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11",
-    };
+    ];
 
     [Fact]
     public void ResolvePart1__Example()
     {
         Day04 day = new();
-        
+
         string result = day.ResolvePart1(_example);
 
         Assert.Equal("13", result);
@@ -25,7 +25,7 @@ public class Day04_Tests
     public void ResolvePart2__Example()
     {
         Day04 day = new();
-        
+
         string result = day.ResolvePart2(_example);
 
         Assert.Equal("30", result);

AdventOfCode2023.Tests/Day05_Tests.cs

@@ -2,7 +2,7 @@ namespace AdventOfCode2023.Tests;
 
 public class Day05_Tests
 {
-    private readonly string[] _example = {
+    private readonly string[] _example = [
         "seeds: 79 14 55 13",
         "",
         "seed-to-soil map:",
@@ -36,13 +36,13 @@ public class Day05_Tests
         "humidity-to-location map:",
         "60 56 37",
         "56 93 4",
-    };
+    ];
 
     [Fact]
     public void ResolvePart1__Example()
     {
         Day05 day = new();
-        
+
         string result = day.ResolvePart1(_example);
 
         Assert.Equal("35", result);
@@ -52,7 +52,7 @@ public class Day05_Tests
     public void ResolvePart2__Example()
     {
         Day05 day = new();
-        
+
         string result = day.ResolvePart2(_example);
 
         Assert.Equal("46", result);
@@ -61,22 +61,22 @@ public class Day05_Tests
     [Fact]
     public void AlmanacMapping_ParseNext__Empty__Null()
     {
-        Day05.LinesReader reader = new(Array.Empty<string>());
+        Day05.LinesReader reader = new([]);
         Day05.AlmanacMapping? mapping = Day05.AlmanacMapping.ParseNext(reader);
-        
+
         Assert.Null(mapping);
     }
-    
+
     [Fact]
     public void AlmanacMapping_ParseNext__Example1()
     {
-        Day05.LinesReader reader = new(new[] { 
+        Day05.LinesReader reader = new([
             "seed-to-soil map:",
             "50 98 2",
             "52 50 48",
-        });
+        ]);
         Day05.AlmanacMapping? mapping = Day05.AlmanacMapping.ParseNext(reader);
-        
+
         Assert.NotNull(mapping);
         Assert.Equal("seed-to-soil", mapping.Name);
         Assert.Equal(2, mapping.RangeMappings.Count);
@@ -90,11 +90,11 @@ public class Day05_Tests
         const long value1 = 100;
         long valueMapped1 = mapping.Apply(value1);
         Assert.Equal(100, valueMapped1);
-        
+
         const long value2 = 99;
         long valueMapped2 = mapping.Apply(value2);
         Assert.Equal(51, valueMapped2);
-        
+
         const long value3 = 45;
         long valueMapped3 = mapping.Apply(value3);
         Assert.Equal(45, valueMapped3);
@@ -109,7 +109,7 @@ public class Day05_Tests
             DestinationStart = 1000,
             Length = 10,
         };
-        
+
         // ..........■■■■■■■■■■..........
         // #####.........................
         Day05.AlmanacRangeMapping range_Lower = new() {
@@ -124,7 +124,7 @@ public class Day05_Tests
         Assert.Equal(5, range_Lower_Result.PreClip.Value.Length);
         Assert.Null(range_Lower_Result.Clipped);
         Assert.Null(range_Lower_Result.PostClip);
-        
+
         // ..........■■■■■■■■■■..........
         // ##########....................
         Day05.AlmanacRangeMapping range_LowerTouching = new() {
@@ -139,7 +139,7 @@ public class Day05_Tests
         Assert.Equal(10, range_LowerTouching_Result.PreClip.Value.Length);
         Assert.Null(range_LowerTouching_Result.Clipped);
         Assert.Null(range_LowerTouching_Result.PostClip);
-        
+
         // ..........■■■■■■■■■■..........
         // .........................#####
         Day05.AlmanacRangeMapping range_Upper = new() {
@@ -154,7 +154,7 @@ public class Day05_Tests
         Assert.Equal(25, range_Upper_Result.PostClip.Value.OriginStart);
         Assert.Equal(25, range_Upper_Result.PostClip.Value.DestinationStart);
         Assert.Equal(5, range_Upper_Result.PostClip.Value.Length);
-        
+
         // ..........■■■■■■■■■■..........
         // ....................##########
         Day05.AlmanacRangeMapping range_UpperTouching = new() {
@@ -169,7 +169,7 @@ public class Day05_Tests
         Assert.Equal(20, range_UpperTouching_Result.PostClip.Value.OriginStart);
         Assert.Equal(20, range_UpperTouching_Result.PostClip.Value.DestinationStart);
         Assert.Equal(10, range_UpperTouching_Result.PostClip.Value.Length);
-        
+
         // ..........■■■■■■■■■■..........
         // ..........$$$$$$$$$$..........
         Day05.AlmanacRangeMapping range_IntersectCover = new() {
@@ -184,7 +184,7 @@ public class Day05_Tests
         Assert.Equal(1000, range_IntersectCover_Result.Clipped.Value.DestinationStart);
         Assert.Equal(10, range_IntersectCover_Result.Clipped.Value.Length);
         Assert.Null(range_IntersectCover_Result.PostClip);
-        
+
         // ..........■■■■■■■■■■..........
         // ...............$$$$$..........
         Day05.AlmanacRangeMapping range_IntersectInsideToEnd = new() {
@@ -199,7 +199,7 @@ public class Day05_Tests
         Assert.Equal(1005, range_IntersectInsideToEnd_Result.Clipped.Value.DestinationStart);
         Assert.Equal(5, range_IntersectInsideToEnd_Result.Clipped.Value.Length);
         Assert.Null(range_IntersectInsideToEnd_Result.PostClip);
-        
+
         // ..........■■■■■■■■■■..........
         // ...............$$$$$#####.....
         Day05.AlmanacRangeMapping range_IntersectInsideToOutside = new() {
@@ -217,7 +217,7 @@ public class Day05_Tests
         Assert.Equal(20, range_IntersectInsideToOutside_Result.PostClip.Value.OriginStart);
         Assert.Equal(20, range_IntersectInsideToOutside_Result.PostClip.Value.DestinationStart);
         Assert.Equal(5, range_IntersectInsideToOutside_Result.PostClip.Value.Length);
-        
+
         // ..........■■■■■■■■■■..........
         // .....#####$$$$$...............
         Day05.AlmanacRangeMapping range_IntersectOutsideToInside = new() {
@@ -235,7 +235,7 @@ public class Day05_Tests
         Assert.Equal(1000, range_IntersectOutsideToInside_Result.Clipped.Value.DestinationStart);
         Assert.Equal(5, range_IntersectOutsideToInside_Result.Clipped.Value.Length);
         Assert.Null(range_IntersectOutsideToInside_Result.PostClip);
-        
+
         // ..........■■■■■■■■■■..........
         // .....#####$$$$$$$$$$..........
         Day05.AlmanacRangeMapping range_IntersectOutsideToEnd = new() {
@@ -253,7 +253,7 @@ public class Day05_Tests
         Assert.Equal(1000, range_IntersectOutsideToEnd_Result.Clipped.Value.DestinationStart);
         Assert.Equal(10, range_IntersectOutsideToEnd_Result.Clipped.Value.Length);
         Assert.Null(range_IntersectOutsideToEnd_Result.PostClip);
-        
+
         // ..........■■■■■■■■■■..........
         // .....#####$$$$$$$$$$#####.....
         Day05.AlmanacRangeMapping range_IntersectOutsideToOutside = new() {

AdventOfCode2023.Tests/Day06_Tests.cs

@@ -2,16 +2,16 @@ namespace AdventOfCode2023.Tests;
 
 public class Day06_Tests
 {
-    private readonly string[] _example = {
+    private readonly string[] _example = [
         "Time:      7  15   30",
         "Distance:  9  40  200",
-    };
+    ];
 
     [Fact]
     public void ResolvePart1__Example()
     {
         Day06 day = new();
-        
+
         string result = day.ResolvePart1(_example);
 
         Assert.Equal("288", result);
@@ -21,7 +21,7 @@ public class Day06_Tests
     public void ResolvePart2__Example()
     {
         Day06 day = new();
-        
+
         string result = day.ResolvePart2(_example);
 
         Assert.Equal("71503", result);

AdventOfCode2023.Tests/Day07_Tests.cs

@@ -2,19 +2,19 @@ namespace AdventOfCode2023.Tests;
 
 public class Day07_Tests
 {
-    private readonly string[] _example = {
+    private readonly string[] _example = [
         "32T3K 765",
         "T55J5 684",
         "KK677 28",
         "KTJJT 220",
         "QQQJA 483",
-    };
+    ];
 
     [Fact]
     public void ResolvePart1__Example()
     {
         Day07 day = new();
-        
+
         string result = day.ResolvePart1(_example);
 
         Assert.Equal("6440", result);
@@ -24,7 +24,7 @@ public class Day07_Tests
     public void ResolvePart2__Example()
     {
         Day07 day = new();
-        
+
         string result = day.ResolvePart2(_example);
 
         Assert.Equal("5905", result);
@@ -35,26 +35,26 @@ public class Day07_Tests
     {
         Day07.CamelCard card_FiveOfAKind = new("AAAAA");
         Assert.Equal(Day07.CamelCard.Types.FiveOfAKind, card_FiveOfAKind.Type);
-        
+
         Day07.CamelCard card_FourOfAKind = new("AA8AA");
         Assert.Equal(Day07.CamelCard.Types.FourOfAKind, card_FourOfAKind.Type);
-        
+
         Day07.CamelCard card_FullHouse = new("23332");
         Assert.Equal(Day07.CamelCard.Types.FullHouse, card_FullHouse.Type);
-        
+
         Day07.CamelCard card_ThreeOfAKind = new("TTT98");
         Assert.Equal(Day07.CamelCard.Types.ThreeOfAKind, card_ThreeOfAKind.Type);
-        
+
         Day07.CamelCard card_TwoPair = new("23432");
         Assert.Equal(Day07.CamelCard.Types.TwoPair, card_TwoPair.Type);
-        
+
         Day07.CamelCard card_OnePair = new("A23A4");
         Assert.Equal(Day07.CamelCard.Types.OnePair, card_OnePair.Type);
-        
+
         Day07.CamelCard card_HighCard = new("23456");
         Assert.Equal(Day07.CamelCard.Types.HighCard, card_HighCard.Type);
     }
-    
+
     [Fact]
     public void CamelCard_CompareTo__Examples()
     {
@@ -62,7 +62,7 @@ public class Day07_Tests
         Day07.CamelCard card_02 = new("2AAAA");
         Assert.Equal(-1, card_01.CompareTo(card_02));
         Assert.Equal(1, card_02.CompareTo(card_01));
-        
+
         Day07.CamelCard card_77888 = new("77888");
         Day07.CamelCard card_77788 = new("77788");
         Assert.Equal(-1, card_77888.CompareTo(card_77788));

AdventOfCode2023.Tests/Day08_Tests.cs

@@ -2,7 +2,7 @@ namespace AdventOfCode2023.Tests;
 
 public class Day08_Tests
 {
-    private readonly string[] _example1 = {
+    private readonly string[] _example1 = [
         "RL",
         "",
         "AAA = (BBB, CCC)",
@@ -12,37 +12,37 @@ public class Day08_Tests
         "EEE = (EEE, EEE)",
         "GGG = (GGG, GGG)",
         "ZZZ = (ZZZ, ZZZ)",
-    };
+    ];
-    
+
     [Fact]
     public void ResolvePart1__Example1()
     {
         Day08 day = new();
-        
+
         string result = day.ResolvePart1(_example1);
 
         Assert.Equal("2", result);
     }
 
-    private readonly string[] _example2 = {
+    private readonly string[] _example2 = [
         "LLR",
         "",
         "AAA = (BBB, BBB)",
         "BBB = (AAA, ZZZ)",
         "ZZZ = (ZZZ, ZZZ)",
-    };
+    ];
 
     [Fact]
     public void ResolvePart1__Example2()
     {
         Day08 day = new();
-        
+
         string result = day.ResolvePart1(_example2);
 
         Assert.Equal("6", result);
     }
 
-    private readonly string[] _example3 = {
+    private readonly string[] _example3 = [
         "LR",
         "",
         "11A = (11B, XXX)",
@@ -53,16 +53,15 @@ public class Day08_Tests
         "22C = (22Z, 22Z)",
         "22Z = (22B, 22B)",
         "XXX = (XXX, XXX)",
-    };
+    ];
 
     [Fact]
     public void ResolvePart2__Example3()
     {
         Day08 day = new();
-        
+
         string result = day.ResolvePart2(_example3);
 
         Assert.Equal("6", result);
     }
-
 }

AdventOfCode2023.Tests/Day09_Tests.cs

@@ -2,17 +2,17 @@ namespace AdventOfCode2023.Tests;
 
 public class Day09_Tests
 {
-    private readonly string[] _example = {
+    private readonly string[] _example = [
         "0 3 6 9 12 15",
         "1 3 6 10 15 21",
         "10 13 16 21 30 45",
-    };
+    ];
 
     [Fact]
     public void ResolvePart1__Example()
     {
         Day09 day = new();
-        
+
         string result = day.ResolvePart1(_example);
 
         Assert.Equal("114", result);
@@ -22,7 +22,7 @@ public class Day09_Tests
     public void ResolvePart2__Example()
     {
         Day09 day = new();
-        
+
         string result = day.ResolvePart2(_example);
 
         Assert.Equal("2", result);
@@ -35,7 +35,7 @@ public class Day09_Tests
         long result = extrapolator.Extrapolate();
         Assert.Equal(18, result);
     }
-    
+
     [Fact]
     public void Extrapolator_Extrapolate__Example2()
     {
@@ -43,7 +43,7 @@ public class Day09_Tests
         long result = extrapolator.Extrapolate();
         Assert.Equal(28, result);
     }
-    
+
     [Fact]
     public void Extrapolator_Extrapolate__Example3()
     {
@@ -59,7 +59,7 @@ public class Day09_Tests
         long result = extrapolator.ExtrapolatePast();
         Assert.Equal(-3, result);
     }
-    
+
     [Fact]
     public void Extrapolator_ExtrapolatePast__Example2()
     {
@@ -67,7 +67,7 @@ public class Day09_Tests
         long result = extrapolator.ExtrapolatePast();
         Assert.Equal(0, result);
     }
-    
+
     [Fact]
     public void Extrapolator_ExtrapolatePast__Example3()
     {

AdventOfCode2023.Tests/Day10_Tests.cs

@@ -2,25 +2,25 @@ namespace AdventOfCode2023.Tests;
 
 public class Day10_Tests
 {
-    private readonly string[] _example1 = {
+    private readonly string[] _example1 = [
         "7-F7-",
         ".FJ|7",
         "SJLL7",
         "|F--J",
         "LJ.LJ",
-    };
+    ];
 
     [Fact]
     public void ResolvePart1__Example1()
     {
         Day10 day = new();
-        
+
         string result = day.ResolvePart1(_example1);
 
         Assert.Equal("8", result);
     }
-    
+
-    private readonly string[] _example2 = {
+    private readonly string[] _example2 = [
         "...........",
         ".S-------7.",
         ".|F-----7|.",
@@ -30,20 +30,20 @@ public class Day10_Tests
         ".|..|.|..|.",
         ".L--J.L--J.",
         "...........",
-    };
+    ];
 
     [Fact]
     public void ResolvePart2__Example2()
     {
         Day10 day = new();
-        
+
         string result = day.ResolvePart2(_example2);
 
         Assert.Equal("4", result);
     }
 
-    
+
-    private readonly string[] _example3 = {
+    private readonly string[] _example3 = [
         "FF7FSF7F7F7F7F7F---7",
         "L|LJ||||||||||||F--J",
         "FL-7LJLJ||||||LJL-77",
@@ -54,13 +54,13 @@ public class Day10_Tests
         "7-L-JL7||F7|L7F-7F7|",
         "L.L7LFJ|||||FJL7||LJ",
         "L7JLJL-JLJLJL--JLJ.L",
-    };
+    ];
 
     [Fact]
     public void ResolvePart2__Example3()
     {
         Day10 day = new();
-        
+
         string result = day.ResolvePart2(_example3);
 
         Assert.Equal("10", result);

AdventOfCode2023.Tests/Day11_Tests.cs

@@ -2,7 +2,7 @@ namespace AdventOfCode2023.Tests;
 
 public class Day11_Tests
 {
-    private readonly string[] _example1 = {
+    private readonly string[] _example1 = [
         "...#......",
         ".......#..",
         "#.........",
@@ -13,16 +13,15 @@ public class Day11_Tests
         "..........",
         ".......#..",
         "#...#.....",
-    };
+    ];
 
     [Fact]
     public void ResolvePart1__Example1()
     {
         Day11 day = new();
-        
+
         string result = day.ResolvePart1(_example1);
 
         Assert.Equal("374", result);
     }
-
 }

AdventOfCode2023.Tests/Day12_Tests.cs

@@ -2,14 +2,14 @@ namespace AdventOfCode2023.Tests;
 
 public class Day12_Tests
 {
-    private readonly string[] _example1 = {
+    private readonly string[] _example1 = [
         "???.### 1,1,3",
         ".??..??...?##. 1,1,3",
         "?#?#?#?#?#?#?#? 1,3,1,6",
         "????.#...#... 4,1,1",
         "????.######..#####. 1,6,5",
         "?###???????? 3,2,1",
-    };
+    ];
 
     [Fact]
     public void ResolvePart1__Example1()

AdventOfCode2023.Tests/Day24_Tests.cs

@@ -10,14 +10,14 @@ namespace AdventOfCode2023.Tests;
 
 public class Day24_Tests
 {
-    private string[] _example1 = {
+    private string[] _example1 = [
         "19, 13, 30 @ -2,  1, -2",
         "18, 19, 22 @ -1, -1, -2",
         "20, 25, 34 @ -2, -2, -4",
         "12, 31, 28 @ -1, -2, -1",
         "20, 19, 15 @  1, -5, -3",
-    };
+    ];
-    
+
     [Fact]
     public void ResolvePart1__Example1()
     {
@@ -36,36 +36,35 @@ public class Day24_Tests
         Day24.Hail hailC = new("20, 25, 34 @ -2, -2, -4");
         Day24.Hail hailD = new("12, 31, 28 @ -1, -2, -1");
         Day24.Hail hailE = new("20, 19, 15 @  1, -5, -3");
-        
+
         (bool intersect_A_B, _, _, _) = hailA.Intersect2D(hailB);
         Assert.True(intersect_A_B);
-        
+
         (bool intersect_A_C, _, _, _) = hailA.Intersect2D(hailC);
         Assert.True(intersect_A_C);
-        
+
         (bool intersect_A_D, _, _, _) = hailA.Intersect2D(hailD);
         Assert.True(intersect_A_D);
-        
+
         (bool intersect_A_E, _, _, _) = hailA.Intersect2D(hailE);
         Assert.True(intersect_A_E);
-        
+
         (bool intersect_B_C, _, _, _) = hailB.Intersect2D(hailC);
         Assert.False(intersect_B_C);
-        
+
         (bool intersect_B_D, _, _, _) = hailB.Intersect2D(hailD);
         Assert.True(intersect_B_D);
-        
+
         (bool intersect_B_E, _, _, _) = hailB.Intersect2D(hailE);
         Assert.True(intersect_B_E);
-        
+
         (bool intersect_C_D, _, _, _) = hailC.Intersect2D(hailD);
         Assert.True(intersect_C_D);
-        
+
         (bool intersect_C_E, _, _, _) = hailC.Intersect2D(hailE);
         Assert.True(intersect_C_E);
-        
+
         (bool intersect_D_E, _, _, _) = hailD.Intersect2D(hailE);
         Assert.True(intersect_D_E);
     }
-
 }

AdventOfCode2023/AdventOfCode2023.csproj

@@ -2,10 +2,10 @@
 
     <PropertyGroup>
         <OutputType>Exe</OutputType>
-        <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
-        <RootNamespace>AdventOfCode2023</RootNamespace>
         <Nullable>enable</Nullable>
+        <RootNamespace>AdventOfCode2023</RootNamespace>
     </PropertyGroup>
 
     <ItemGroup>
@@ -15,7 +15,7 @@
     </ItemGroup>
 
     <ItemGroup>
-      <ProjectReference Include="..\AdventOfCode.Common\AdventOfCode.Common.csproj" />
+        <ProjectReference Include="..\AdventOfCode.Common\AdventOfCode.Common.csproj"/>
     </ItemGroup>
 
 </Project>

AdventOfCode2023/Day01.cs

@@ -78,7 +78,7 @@ public class Day01 : IDay
 
     public string ResolvePart2(string[] inputs)
     {
-        List<(string Text, int Value)> digits = new() {
+        List<(string Text, int Value)> digits = [
             ("1", 1),
             ("2", 2),
             ("3", 3),
@@ -97,7 +97,7 @@ public class Day01 : IDay
             ("seven", 7),
             ("eight", 8),
             ("nine", 9),
-        };
+        ];
 
         int sum = 0;
         foreach (string line in inputs)

AdventOfCode2023/Day03.cs

@@ -102,7 +102,7 @@ public class Day03 : IDay
             for (column = 0; column < inputs[row].Length; column++)
             {
                 if (inputs[row][column] != '*') { continue; }
-                
+
                 List<SchemaNumber> adjacentNumbers = numbers.Where(n => CellAdjacentToSchemaNumber(row, column, n)).ToList();
                 if (adjacentNumbers.Count != 2) { continue; }
 
@@ -115,11 +115,11 @@ public class Day03 : IDay
 
     public struct SchemaNumber
     {
-        public string[] Schema { get; set; }
+        public string[] Schema { get; init; }
-        public int Row { get; set; }
+        public int Row { get; init; }
-        public int Column { get; set; }
+        public int Column { get; init; }
-        public int Lenght { get; set; }
+        public int Lenght { get; init; }
-        public int Value { get; set; }
+        public int Value { get; init; }
     }
 
     public static SchemaNumber? SearchNextSchemaNumber(string[] schema, int initialRow, int initialColumn)
@@ -176,7 +176,7 @@ public class Day03 : IDay
         }
         return false;
     }
-    
+
     private static bool CellAdjacentToSchemaNumber(int row, int column, SchemaNumber number)
     {
         int minRow = number.Row - 1;
@@ -188,8 +188,7 @@ public class Day03 : IDay
         {
             return true;
         }
-        
+
         return false;
     }
-
 }

AdventOfCode2023/Day04.cs

@@ -118,7 +118,7 @@ public class Day04 : IDay
             _winningNumbers = GetNumbers(strColumns[0]);
             _myNumbers = GetNumbers(strColumns[1]);
         }
-        
+
         private static List<int> GetNumbers(string strNumbers)
         {
             string[] parts = strNumbers.Split(' ');
@@ -135,6 +135,5 @@ public class Day04 : IDay
         {
             return _myNumbers.Count(myNumber => _winningNumbers.Contains(myNumber));
         }
-        
     }
 }

AdventOfCode2023/Day05.cs

@@ -136,7 +136,7 @@ public class Day05 : IDay
         LinesReader reader = new(inputs);
         Almanac? almanac = Almanac.Parse(reader);
         int i = 0;
-        List<AlmanacRangeMapping> ranges = new();
+        List<AlmanacRangeMapping> ranges = [];
         while (almanac?.Seeds.Count > i)
         {
             long seed = almanac.Seeds[i];
@@ -155,21 +155,14 @@ public class Day05 : IDay
     }
 
 
-    public class LinesReader
+    public class LinesReader(string[] lines)
     {
-        private readonly string[] _lines;
         private int _index;
 
-        public LinesReader(string[] lines)
-        {
-            _lines = lines;
-            _index = 0;
-        }
-
         public string? GetLine()
         {
-            if (_index >= _lines.Length) { return null; }
+            if (_index >= lines.Length) { return null; }
-            string line = _lines[_index];
+            string line = lines[_index];
             _index++;
             return line;
         }
@@ -298,7 +291,7 @@ public class Day05 : IDay
     {
         public string Name { get; private init; } = string.Empty;
 
-        public List<AlmanacRangeMapping> RangeMappings { get; } = new();
+        public List<AlmanacRangeMapping> RangeMappings { get; } = [];
 
         public static AlmanacMapping? ParseNext(LinesReader reader)
         {
@@ -346,29 +339,32 @@ public class Day05 : IDay
 
         public List<AlmanacRangeMapping> Apply(AlmanacRangeMapping range)
         {
-            List<AlmanacRangeMapping> unMappedRanges = new() {
+            List<AlmanacRangeMapping> unMappedRanges = [
                 range,
-            };
+            ];
-            List<AlmanacRangeMapping> newUnMappedRanges = new();
+            List<AlmanacRangeMapping> newUnMappedRanges = [];
-            List<AlmanacRangeMapping> mappedRanges = new();
+            List<AlmanacRangeMapping> mappedRanges = [];
 
             int i = 0;
             while (RangeMappings.Count > i)
             {
                 AlmanacRangeMapping rangeMapping = RangeMappings[i];
-                for (int j = 0; j < unMappedRanges.Count; j++)
+                foreach (AlmanacRangeMapping unMappedRange in unMappedRanges)
                 {
-                    AlmanacRangeMapping.ClipResult result = rangeMapping.Clip(unMappedRanges[j]);
+                    AlmanacRangeMapping.ClipResult result = rangeMapping.Clip(unMappedRange);
                     if (result.Clipped != null) { mappedRanges.Add(result.Clipped.Value); }
                     if (result.PreClip != null) { newUnMappedRanges.Add(result.PreClip.Value); }
                     if (result.PostClip != null) { newUnMappedRanges.Add(result.PostClip.Value); }
                 }
                 unMappedRanges = newUnMappedRanges;
-                newUnMappedRanges = new List<AlmanacRangeMapping>();
+                newUnMappedRanges = [];
                 i++;
             }
 
-            return mappedRanges.Union(unMappedRanges).ToList();
+            List<AlmanacRangeMapping> resultMappedRanges = [];
+            resultMappedRanges.AddRange(mappedRanges);
+            resultMappedRanges.AddRange(unMappedRanges);
+            return resultMappedRanges;
         }
     }
 
@@ -381,7 +377,7 @@ public class Day05 : IDay
 
         public List<long> Seeds { get; }
 
-        private List<AlmanacMapping> Mappings { get; } = new();
+        private List<AlmanacMapping> Mappings { get; } = [];
 
         public static Almanac? Parse(LinesReader reader)
         {

AdventOfCode2023/Day07.cs

@@ -114,9 +114,9 @@ public class Day07 : IDay
 
     public class CamelCard
     {
-        private readonly static char[] Labels = { 'A', 'K', 'Q', 'J', 'T', '9', '8', '7', '6', '5', '4', '3', '2' };
+        private readonly static char[] Labels = ['A', 'K', 'Q', 'J', 'T', '9', '8', '7', '6', '5', '4', '3', '2'];
 
-        private readonly static char[] LabelsWithJoker = { 'A', 'K', 'Q', 'T', '9', '8', '7', '6', '5', '4', '3', '2', 'J' };
+        private readonly static char[] LabelsWithJoker = ['A', 'K', 'Q', 'T', '9', '8', '7', '6', '5', '4', '3', '2', 'J'];
         private const char JokerLabel = 'J';
 
         public enum Types
@@ -174,7 +174,7 @@ public class Day07 : IDay
                     dictLabelCounts.Add(JokerLabel, 5);
                 }
             }
-            
+
             if (dictLabelCounts.Count == 1) { return Types.FiveOfAKind; }
             if (dictLabelCounts.Count == 5) { return Types.HighCard; }
             if (dictLabelCounts.Count == 2)

AdventOfCode2023/Day08.cs

@@ -105,18 +105,11 @@ public class Day08 : IDay
         return steps.ToString();
     }
 
-    private class MapNode
+    private class MapNode(string strMapNode)
     {
-        public string Key { get; set; }
+        public string Key { get; } = strMapNode.Substring(0, 3);
-        public string LeftKey { get; set; }
+        public string LeftKey { get; } = strMapNode.Substring(7, 3);
-        public string RightKey { get; set; }
+        public string RightKey { get; } = strMapNode.Substring(12, 3);
-
-        public MapNode(string strMapNode)
-        {
-            Key = strMapNode.Substring(0, 3);
-            LeftKey = strMapNode.Substring(7, 3);
-            RightKey = strMapNode.Substring(12, 3);
-        }
     }
 
     private class Map
@@ -155,32 +148,23 @@ public class Day08 : IDay
         }
     }
 
-    private class MapWalker
+    private class MapWalker(Map map, string startKey)
     {
-        private readonly Map _map;
+        private MapNode _currentNode = map.GetByKey(startKey) ?? map.Nodes.First();
-
-        private MapNode _currentNode;
         private long _steps;
 
-        public MapWalker(Map map, string startKey)
-        {
-            _map = map;
-            _currentNode = map.GetByKey(startKey) ?? map.Nodes.First();
-            _steps = 0;
-        }
-
         public void StepWhile(Func<MapWalker, bool> condition)
         {
             while (condition(this))
             {
-                char leftRightInstruction = _map.GetInstruction(_steps);
+                char leftRightInstruction = map.GetInstruction(_steps);
                 if (leftRightInstruction == 'L')
                 {
-                    _currentNode = _map.GetByKey(_currentNode.LeftKey) ?? _map.Nodes.First();
+                    _currentNode = map.GetByKey(_currentNode.LeftKey) ?? map.Nodes.First();
                 }
                 if (leftRightInstruction == 'R')
                 {
-                    _currentNode = _map.GetByKey(_currentNode.RightKey) ?? _map.Nodes.First();
+                    _currentNode = map.GetByKey(_currentNode.RightKey) ?? map.Nodes.First();
                 }
                 _steps++;
             }
@@ -196,7 +180,7 @@ public class Day08 : IDay
             get { return _steps; }
         }
     }
-    
+
     // https://en.wikipedia.org/wiki/Euclidean_algorithm#Implementations
     private static long GreatestCommonDivisor(long a, long b)
     {

AdventOfCode2023/Day09.cs

@@ -164,15 +164,15 @@ public class Day09 : IDay
 
             return newLastNumber;
         }
-        
+
         public long ExtrapolatePast()
         {
-            _derivatives.Last().Insert(0,0);
+            _derivatives.Last().Insert(0, 0);
             for (int i = _derivatives.Count - 2; i >= 0; i--)
             {
                 long firstDerivative1 = _derivatives[i].First();
                 long firstDerivative0 = _derivatives[i + 1].First();
-                _derivatives[i].Insert(0,firstDerivative1 - firstDerivative0);
+                _derivatives[i].Insert(0, firstDerivative1 - firstDerivative0);
             }
             long firstNumber = _numbers.First();
             long firstDerivative = _derivatives[0].First();

AdventOfCode2023/Day10.cs

@@ -228,16 +228,10 @@ public class Day10 : IDay
         return countInside.ToString();
     }
 
-    private struct Point
+    private struct Point(int x, int y)
     {
-        public int X;
+        public int X = x;
-        public int Y;
+        public int Y = y;
-
-        public Point(int x, int y)
-        {
-            X = x;
-            Y = y;
-        }
     }
 
     private class PipeMaze
@@ -323,7 +317,7 @@ public class Day10 : IDay
                         x: point.X + 1,
                         y: point.Y);
                 }
-                if(point.Y == prevPoint.Y && prevPoint.X > point.X)
+                if (point.Y == prevPoint.Y && prevPoint.X > point.X)
                 {
                     return new Point(
                         x: point.X,
@@ -339,7 +333,7 @@ public class Day10 : IDay
                         x: point.X - 1,
                         y: point.Y);
                 }
-                if(point.Y == prevPoint.Y && prevPoint.X < point.X)
+                if (point.Y == prevPoint.Y && prevPoint.X < point.X)
                 {
                     return new Point(
                         x: point.X,
@@ -355,7 +349,7 @@ public class Day10 : IDay
                         x: point.X - 1,
                         y: point.Y);
                 }
-                if(point.Y == prevPoint.Y && prevPoint.X < point.X)
+                if (point.Y == prevPoint.Y && prevPoint.X < point.X)
                 {
                     return new Point(
                         x: point.X,
@@ -371,7 +365,7 @@ public class Day10 : IDay
                         x: point.X + 1,
                         y: point.Y);
                 }
-                if(point.Y == prevPoint.Y && prevPoint.X > point.X)
+                if (point.Y == prevPoint.Y && prevPoint.X > point.X)
                 {
                     return new Point(
                         x: point.X,
@@ -397,7 +391,7 @@ public class Day10 : IDay
             {
                 Point? nextPoint = FollowPipe(point, prevPoint);
                 if (nextPoint == null) { break; }
-                
+
                 distance++;
                 int? currentDistance = GetDistance(point);
                 if (currentDistance > distance || currentDistance == null)
@@ -409,7 +403,7 @@ public class Day10 : IDay
                 point = nextPoint.Value;
             } while (true);
         }
-        
+
         public int GetMaxDistance()
         {
             int max = int.MinValue;
@@ -438,10 +432,10 @@ public class Day10 : IDay
 
         private char CalculateCell(Point point)
         {
-            Point? pointRight =FollowPipe(new Point(point.X + 1, point.Y), point);
+            Point? pointRight = FollowPipe(new Point(point.X + 1, point.Y), point);
-            Point? pointLeft =FollowPipe(new Point(point.X - 1, point.Y), point);
+            Point? pointLeft = FollowPipe(new Point(point.X - 1, point.Y), point);
-            Point? pointDown =FollowPipe(new Point(point.X, point.Y + 1), point);
+            Point? pointDown = FollowPipe(new Point(point.X, point.Y + 1), point);
-            Point? pointUp =FollowPipe(new Point(point.X, point.Y - 1), point);
+            Point? pointUp = FollowPipe(new Point(point.X, point.Y - 1), point);
             if (pointRight != null && pointLeft == null && pointDown != null && pointUp == null)
             {
                 return 'F';
@@ -507,12 +501,12 @@ public class Day10 : IDay
                     }
                     else if (cell == 'J')
                     {
-                        if(cellStart == 'F')
+                        if (cellStart == 'F')
                         {
                             inside = inside != true;
                             cellStart = null;
                         }
-                        else if(cellStart == 'L')
+                        else if (cellStart == 'L')
                         {
                             cellStart = null;
                         }
@@ -523,23 +517,23 @@ public class Day10 : IDay
                         {
                             cellStart = 'F';
                         }
-                        else if(cellStart == 'J')
+                        else if (cellStart == 'J')
                         {
                             inside = inside != true;
                             cellStart = null;
                         }
-                        else if(cellStart == '7')
+                        else if (cellStart == '7')
                         {
                             cellStart = null;
                         }
                     }
                     else if (cell == '7')
                     {
-                        if(cellStart == 'F')
+                        if (cellStart == 'F')
                         {
                             cellStart = null;
                         }
-                        else if(cellStart == 'L')
+                        else if (cellStart == 'L')
                         {
                             inside = inside != true;
                             cellStart = null;
@@ -551,11 +545,11 @@ public class Day10 : IDay
                         {
                             cellStart = 'L';
                         }
-                        else if(cellStart == 'J')
+                        else if (cellStart == 'J')
                         {
                             cellStart = null;
                         }
-                        else if(cellStart == '7')
+                        else if (cellStart == '7')
                         {
                             inside = inside != true;
                             cellStart = null;

AdventOfCode2023/Day11.cs

@@ -130,8 +130,8 @@ public class Day11 : IDay
 
     private struct Point
     {
-        public long X { get; set; }
+        public long X { get; init; }
-        public long Y { get; set; }
+        public long Y { get; init; }
     }
 
     private class GalaxyMap

AdventOfCode2023/Day12.cs

@@ -1,4 +1,3 @@
-using System.Text;
 
 namespace AdventOfCode2023;
 
@@ -212,7 +211,7 @@ public class Day12 : IDay
             {
                 throw new Exception("Invalid input");
             }
-            
+
             if (springsRecord.Length < damagedSprings[0])
             {
                 // Invalid match; Not enough data on record for the current damagedSprings group
@@ -230,7 +229,7 @@ public class Day12 : IDay
                 // Skip current damagedSprings group
                 return CountPossibleArrangements(springsRecord.Substring(damagedSprings[0]), damagedSprings.Skip(1).ToArray());
             }
-                
+
             if (springsRecord.Length < (damagedSprings[0] + 1) || springsRecord[damagedSprings[0]] == '#')
             {
                 // Invalid match; There must be an operational (or unknown) spring between damaged spring groups

AdventOfCode2023/Day24.cs

@@ -103,24 +103,17 @@ public class Day24 : IDay
         throw new NotImplementedException();
     }
 
-    public struct Vector3D
+    public struct Vector3D(long x, long y, long z)
     {
-        public readonly long X;
+        public readonly long X = x;
-        public readonly long Y;
+        public readonly long Y = y;
-        public readonly long Z;
+        public readonly long Z = z;
-
-        public Vector3D(long x, long y, long z)
-        {
-            X = x;
-            Y = y;
-            Z = z;
-        }
     }
 
     public readonly struct Hail
     {
         public readonly Vector3D Position;
-        public readonly Vector3D Velocity;
+        private readonly Vector3D _velocity;
 
         public Hail(string input)
         {
@@ -131,7 +124,7 @@ public class Day24 : IDay
                 y: Convert.ToInt64(strPosition[1]),
                 z: Convert.ToInt64(strPosition[2]));
             string[] strVelocity = parts[1].Split(", ");
-            Velocity = new Vector3D(
+            _velocity = new Vector3D(
                 x: Convert.ToInt64(strVelocity[0]),
                 y: Convert.ToInt64(strVelocity[1]),
                 z: Convert.ToInt64(strVelocity[2]));
@@ -139,21 +132,21 @@ public class Day24 : IDay
 
         public (bool intersects, double s, double t, Vector3D point) Intersect2D(Hail other)
         {
-            long s_Div = (-other.Velocity.X * Velocity.Y + Velocity.X * other.Velocity.Y);
+            long s_Div = (-other._velocity.X * _velocity.Y + _velocity.X * other._velocity.Y);
             if (s_Div == 0)
             {
                 return (false, 0, 0, new Vector3D());
             }
-            double s = (-Velocity.Y * (Position.X - other.Position.X) + Velocity.X * (Position.Y - other.Position.Y)) / (double)s_Div;
+            double s = (-_velocity.Y * (Position.X - other.Position.X) + _velocity.X * (Position.Y - other.Position.Y)) / (double)s_Div;
 
-            long t_Div = (-other.Velocity.X * Velocity.Y + Velocity.X * other.Velocity.Y);
+            long t_Div = (-other._velocity.X * _velocity.Y + _velocity.X * other._velocity.Y);
             if (t_Div == 0)
             {
                 return (false, 0, 0, new Vector3D());
             }
-            double t = (other.Velocity.X * (Position.Y - other.Position.Y) - other.Velocity.Y * (Position.X - other.Position.X)) / (double)t_Div;
+            double t = (other._velocity.X * (Position.Y - other.Position.Y) - other._velocity.Y * (Position.X - other.Position.X)) / (double)t_Div;
 
-            Vector3D intersection = new((long)(Position.X + t * Velocity.X), (long)(Position.Y + t * Velocity.Y), 0);
+            Vector3D intersection = new((long)(Position.X + t * _velocity.X), (long)(Position.Y + t * _velocity.Y), 0);
             return (true, s, t, intersection);
         }
     }

AdventOfCode2024.Tests/AdventOfCode2024.Tests.csproj

@@ -0,0 +1,26 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>net8.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+        <RootNamespace>AdventOfCode2024.Tests</RootNamespace>
+
+        <IsPackable>false</IsPackable>
+        <IsTestProject>true</IsTestProject>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.0"/>
+        <PackageReference Include="xunit" Version="2.4.2"/>
+        <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
+            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+            <PrivateAssets>all</PrivateAssets>
+        </PackageReference>
+    </ItemGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\AdventOfCode2024\AdventOfCode2024.csproj"/>
+    </ItemGroup>
+
+</Project>

AdventOfCode2024.Tests/Day01_Tests.cs

@@ -0,0 +1,38 @@
+namespace AdventOfCode2024.Tests;
+
+public class Day01_Tests
+{
+    [Fact]
+    public void ResolvePart1__Example()
+    {
+        Day01 day = new();
+
+        string result = day.ResolvePart1([
+            "3   4",
+            "4   3",
+            "2   5",
+            "1   3",
+            "3   9",
+            "3   3",
+        ]);
+
+        Assert.Equal("11", result);
+    }
+
+    [Fact]
+    public void ResolvePart2__Example()
+    {
+        Day01 day = new();
+
+        string result = day.ResolvePart2([
+            "3   4",
+            "4   3",
+            "2   5",
+            "1   3",
+            "3   9",
+            "3   3",
+        ]);
+
+        Assert.Equal("31", result);
+    }
+}

AdventOfCode2024.Tests/Day02_Tests.cs

@@ -0,0 +1,38 @@
+namespace AdventOfCode2024.Tests;
+
+public class Day02_Tests
+{
+    [Fact]
+    public void ResolvePart1__Example()
+    {
+        Day02 day = new();
+
+        string result = day.ResolvePart1([
+            "7 6 4 2 1",
+            "1 2 7 8 9",
+            "9 7 6 2 1",
+            "1 3 2 4 5",
+            "8 6 4 4 1",
+            "1 3 6 7 9",
+        ]);
+
+        Assert.Equal("2", result);
+    }
+    
+    [Fact]
+    public void ResolvePart2__Example()
+    {
+        Day02 day = new();
+
+        string result = day.ResolvePart2([
+            "7 6 4 2 1",
+            "1 2 7 8 9",
+            "9 7 6 2 1",
+            "1 3 2 4 5",
+            "8 6 4 4 1",
+            "1 3 6 7 9",
+        ]);
+
+        Assert.Equal("4", result);
+    }
+}