Add Day 6 part 1

AdventOfCode2024.sln

@@ -13,6 +13,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Day4", "Day4\Day4.csproj",
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Day5", "Day5\Day5.csproj", "{F6C4FEFC-795A-45A5-A227-3DCA06749BAD}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Day6", "Day6\Day6.csproj", "{6E7CF4A7-6667-4081-9E54-36452956EE8C}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -39,6 +41,10 @@ Global
 		{F6C4FEFC-795A-45A5-A227-3DCA06749BAD}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{F6C4FEFC-795A-45A5-A227-3DCA06749BAD}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{F6C4FEFC-795A-45A5-A227-3DCA06749BAD}.Release|Any CPU.Build.0 = Release|Any CPU
+		{6E7CF4A7-6667-4081-9E54-36452956EE8C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{6E7CF4A7-6667-4081-9E54-36452956EE8C}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{6E7CF4A7-6667-4081-9E54-36452956EE8C}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{6E7CF4A7-6667-4081-9E54-36452956EE8C}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

Day6/Day6.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>net8.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <None Update="input.txt">
+        <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+      </None>
+    </ItemGroup>
+
+</Project>

Day6/Program.cs

@@ -0,0 +1,84 @@
+var lines = File.ReadAllLines("input.txt");
+var charArray = new char[lines.Length, lines[0].Length];
+Dictionary<Direction, (int dx, int dy)> moves = new()
+{
+    { Direction.Up, (-1, 0) },
+    { Direction.Right, (0, 1) },
+    { Direction.Down, (1, 0) },
+    { Direction.Left, (0, -1) }
+};
+
+var guardCurrentPosition = (0, 0);
+var guardDirection = Direction.Up;
+var visitedPositions = new List<int[]>();
+
+for (var i = 0; i < charArray.GetLength(0); i++)
+for (var j = 0; j < charArray.GetLength(1); j++)
+{
+    if (lines[i][j] == '^')
+    {
+        guardCurrentPosition.Item1 = i;
+        guardCurrentPosition.Item2 = j;
+        visitedPositions.Add([guardCurrentPosition.Item1, guardCurrentPosition.Item2]);
+    }
+
+    charArray[i, j] = lines[i][j];
+}
+
+var nextPosition = CalculateNextPosition(guardCurrentPosition.Item1, guardCurrentPosition.Item2, guardDirection);
+
+while (IsValid(nextPosition.Item1, nextPosition.Item2, charArray))
+{
+    if (IsBlocked(nextPosition.Item1, nextPosition.Item2, charArray))
+    {
+        guardDirection = (Direction)(((int)guardDirection + 1) % 4);
+    }
+    else
+    {
+        guardCurrentPosition = (nextPosition.Item1, nextPosition.Item2);
+        visitedPositions.Add([guardCurrentPosition.Item1, guardCurrentPosition.Item2]);
+    }
+
+    nextPosition = CalculateNextPosition(guardCurrentPosition.Item1, guardCurrentPosition.Item2, guardDirection);
+}
+
+Console.WriteLine($"Part1: {visitedPositions.Select(x => $"r{x[0]},c{x[1]}").Distinct().Count()}");
+PrintMap(charArray, visitedPositions);
+
+(int, int) CalculateNextPosition(int row, int col, Direction direction)
+{
+    var (dx, dy) = moves[direction];
+    return (row + dx, col + dy);
+}
+
+bool IsValid(int row, int column, char[,] grid) => row >= 0 && row < grid.GetLength(0) && column >= 0 && column < grid.GetLength(1);
+
+bool IsBlocked(int row, int col, char[,] grid) => grid[row, col] == '#';
+
+void PrintMap(char[,] input, List<int[]> visitedPositions)
+{
+    for (var i = 0; i < input.GetLength(0); i++)
+    {
+        for (var j = 0; j < input.GetLength(1); j++)
+        {
+            if (visitedPositions.Any(x => x[0] == i && x[1] == j) && input[i, j] != '^')
+            {
+                Console.Write("X");
+            }
+            else
+            {
+                Console.Write(input[i, j]);
+            }
+        }
+
+        Console.WriteLine();
+    }
+}
+
+enum Direction
+{
+    Up,
+    Right,
+    Down,
+    Left
+}

Day6/input.txt

@@ -0,0 +1,10 @@
+....#.....
+.........#
+..........
+..#.......
+.......#..
+..........
+.#..^.....
+........#.
+#.........
+......#...