Code for Day06 part 1

AdventOfCode2018.Tests/AdventOfCode2018.Tests.csproj

@@ -56,6 +56,7 @@
     <Otherwise />
   </Choose>
   <ItemGroup>
+    <Compile Include="ChronoPoint_Tests.cs" />
     <Compile Include="Claim_Tests.cs" />
     <Compile Include="Day01_Tests.cs" />
     <Compile Include="Day02_Tests.cs" />

AdventOfCode2018.Tests/ChronoPoint_Tests.cs

@@ -0,0 +1,65 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace AdventOfCode2018.Tests
+{
+    [TestClass()]
+    public class ChronoPoint_Tests
+    {
+        #region FromString
+
+        [TestMethod()]
+        public void FromString__Test1()
+        {
+            ChronoPoint point = ChronoPoint.FromString("1, 1");
+
+            Assert.AreEqual(1, point.X);
+            Assert.AreEqual(1, point.Y);
+        }
+
+        [TestMethod()]
+        public void FromString__Test2()
+        {
+            ChronoPoint point = ChronoPoint.FromString("1, 6");
+
+            Assert.AreEqual(1, point.X);
+            Assert.AreEqual(6, point.Y);
+        }
+
+        [TestMethod()]
+        public void FromString__Test3()
+        {
+            ChronoPoint point = ChronoPoint.FromString("8, 9");
+
+            Assert.AreEqual(8, point.X);
+            Assert.AreEqual(9, point.Y);
+        }
+
+        #endregion FromString
+
+        #region ManhattanDistance
+
+        [TestMethod()]
+        public void ManhattanDistance__Test1()
+        {
+            ChronoPoint p0 = ChronoPoint.FromString("8, 9");
+            ChronoPoint p1 = ChronoPoint.FromString("1, 6");
+
+            int distance = ChronoPoint.ManhattanDistance(p0, p1);
+
+            Assert.AreEqual(10, distance);
+        }
+
+        [TestMethod()]
+        public void ManhattanDistance__Test2()
+        {
+            ChronoPoint p0 = ChronoPoint.FromString("1, 1");
+            ChronoPoint p1 = ChronoPoint.FromString("1, 6");
+
+            int distance = ChronoPoint.ManhattanDistance(p0, p1);
+
+            Assert.AreEqual(5, distance);
+        }
+
+        #endregion ManhattanDistance
+    }
+}

AdventOfCode2018/Day06.cs

@@ -1,4 +1,8 @@
-namespace AdventOfCode2018
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace AdventOfCode2018
 {
     /*
     --- Day 6: Chronal Coordinates ---
@@ -59,7 +63,64 @@
     {
         public string ResolvePart1(string[] inputs)
         {
-            return null;
+            List<ChronoPoint> points = inputs
+                .Where(input => string.IsNullOrEmpty(input) == false)
+                .Select(input => ChronoPoint.FromString(input))
+                .ToList();
+            Dictionary<int, int> pointsAreas = new Dictionary<int, int>();
+            for (int i = 0; i < points.Count; i++)
+            {
+                pointsAreas.Add(i, 0);
+            }
+            
+            int minX = points.Min(p => p.X) - 1;
+            int maxX = points.Max(p => p.X) + 1;
+            int minY = points.Min(p => p.Y) - 1;
+            int maxY = points.Max(p => p.Y) + 1;
+
+            ChronoPoint samplingPoint = new ChronoPoint();
+            for(int i=minX; i <= maxX; i++)
+            {
+                for(int j = minY; j <= maxY; j++)
+                {
+                    samplingPoint.X = i;
+                    samplingPoint.Y = j;
+                    bool isEdge = i == minX || i == maxX || j == minY || j == maxY;
+
+                    int idxMin = -1;
+                    int distanceMin = int.MaxValue;
+                    for (int idx = 0; idx < points.Count; idx++)
+                    {
+                        int distance = ChronoPoint.ManhattanDistance(samplingPoint, points[idx]);
+                        if (distance == distanceMin)
+                        {
+                            idxMin = -1;
+                        }
+                        else if (distance < distanceMin)
+                        {
+                            distanceMin = distance;
+                            idxMin = idx;
+                        }
+                    }
+                    if (idxMin < 0) { continue; }
+
+                    if (isEdge)
+                    {
+                        pointsAreas[idxMin] = -1;
+                    }
+                    else
+                    {
+                        int previousArea = pointsAreas[idxMin];
+                        if (previousArea >= 0)
+                        {
+                            pointsAreas[idxMin] = previousArea + 1;
+                        }
+                    }
+                }
+            }
+
+            int maxArea = pointsAreas.Max(p => p.Value);
+            return maxArea.ToString();
         }
 
         public string ResolvePart2(string[] inputs)
@@ -67,4 +128,29 @@
             return null;
         }
     }
+
+    public class ChronoPoint
+    {
+        public int X { get; set; }
+        public int Y { get; set; }
+
+        public static ChronoPoint FromString(string strPoint)
+        {
+            if (string.IsNullOrEmpty(strPoint)) { return null; }
+            string[] parts = strPoint.Split(new string[] { ", ", }, StringSplitOptions.RemoveEmptyEntries);
+            if (parts.Length < 2) { return null; }
+            ChronoPoint point = new ChronoPoint
+            {
+                X = Convert.ToInt32(parts[0]),
+                Y = Convert.ToInt32(parts[1]),
+            };
+            return point;
+        }
+
+        public static int ManhattanDistance(ChronoPoint p0, ChronoPoint p1)
+        {
+            int distance = Math.Abs(p1.X - p0.X) + Math.Abs(p1.Y - p0.Y);
+            return distance;
+        }
+    }
 }