Add Day 10

AdventOfCode.sln

@@ -1,4 +1,4 @@
-
+
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
 VisualStudioVersion = 17.0.31903.59
@@ -25,6 +25,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "core", "src\core\core.cspro
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "aoc-2024-09", "src\2024\09\aoc-2024-09.csproj", "{BFF5A025-BCA5-426C-AA21-237E1059AEA7}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "aoc-2024-10", "src\2024\10\aoc-2024-10.csproj", "{295CA1CA-AF90-41EC-A077-98D20A00A6AF}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -74,6 +76,10 @@ Global
 		{BFF5A025-BCA5-426C-AA21-237E1059AEA7}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{BFF5A025-BCA5-426C-AA21-237E1059AEA7}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{BFF5A025-BCA5-426C-AA21-237E1059AEA7}.Release|Any CPU.Build.0 = Release|Any CPU
+		{295CA1CA-AF90-41EC-A077-98D20A00A6AF}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{295CA1CA-AF90-41EC-A077-98D20A00A6AF}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{295CA1CA-AF90-41EC-A077-98D20A00A6AF}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{295CA1CA-AF90-41EC-A077-98D20A00A6AF}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{FAF70800-E2C3-4AD7-B433-86C1F20380F7} = {37CA8017-085A-4F6A-BADB-535F929C10B9}
@@ -85,5 +91,6 @@ Global
 		{58941BB2-E4AC-40F0-AA92-BEF51DEFC859} = {37CA8017-085A-4F6A-BADB-535F929C10B9}
 		{44BBC1CF-D2FC-4906-9691-B439EC9EFB8C} = {37CA8017-085A-4F6A-BADB-535F929C10B9}
 		{BFF5A025-BCA5-426C-AA21-237E1059AEA7} = {37CA8017-085A-4F6A-BADB-535F929C10B9}
+		{295CA1CA-AF90-41EC-A077-98D20A00A6AF} = {37CA8017-085A-4F6A-BADB-535F929C10B9}
 	EndGlobalSection
 EndGlobal

src/2024/10/Program.cs

@@ -0,0 +1,88 @@
+using System.Collections;
+using System.Collections.Frozen;
+using System.Numerics;
+using System.Runtime.InteropServices;
+using System.Xml;
+
+using ConsoleAppFramework;
+
+using core;
+
+var builder = ConsoleApp.Create();
+builder.Add("part-one", static ([Argument, FileExists] string file) =>
+{
+	Console.WriteLine($"Result: {ReadFile(file, true)}");
+});
+builder.Add("part-two", static ([Argument, FileExists] string file) =>
+{
+	Console.WriteLine($"Result: {ReadFile(file, false)}");
+});
+builder.Run(args);
+
+static long ReadFile(string file, bool unique)
+{
+	SymbolGrid grid = new();
+	grid.Load(file);
+	ScenarioMap map = new(grid);
+
+	HashSet<Vector2I> startingPositions = [];
+	for (int x = 0; x < map.Width; x++)
+	{
+		for (int y = 0; y < map.Height; y++)
+		{
+			if (map[x, y] == 0)
+			{
+				startingPositions.Add(new(x, y));
+			}
+		}
+	}
+
+
+	long result = 0;
+	foreach (var position in startingPositions)
+	{
+		ICollection<Vector2I> target = unique ? new HashSet<Vector2I>() : new List<Vector2I>();
+		Walk(map, position, target);
+		result += target.Count;
+		Console.WriteLine(target.Count);
+	}
+
+	return result;
+
+	static void Walk(ScenarioMap map, Vector2I currentPosition, ICollection<Vector2I> results)
+	{
+		var height = map[currentPosition];
+		if (height == 9)
+		{
+			results.Add(currentPosition);
+			return;
+		}
+
+		foreach (var d in s_directions.Span)
+		{
+			var newPosition = currentPosition + d;
+			if (!map.IsValid(newPosition))
+			{
+				continue;
+			}
+
+			if ((map[newPosition] - height) != 1)
+			{
+				continue;
+			}
+
+			Walk(map, newPosition, results);
+		}
+	}
+
+}
+
+partial class Program
+{
+	static ReadOnlyMemory<Vector2I> s_directions;
+
+	static Program()
+	{
+		s_directions = (Vector2I[])[new(-1, 0), new(1, 0), new(0, -1), new(0, 1)];
+	}
+}

src/2024/10/ScenarioMap.cs

@@ -0,0 +1,29 @@
+using core;
+
+record class ScenarioMap
+{
+	private readonly int[] _heights;
+
+	public int this[Vector2I position] => this[position.X, position.Y];
+
+	public int this[int x, int y] => _heights[y * Width + x];
+
+	public int Width { get; }
+
+	public int Height { get; }
+
+	public ScenarioMap(SymbolGrid grid)
+	{
+		(Width, Height) = (grid.Width, grid.Height);
+
+		_heights = new int[Width * Height];
+		foreach (var (position, symbol) in grid)
+		{
+			_heights[position.Y * Width + position.X] = symbol - '0';
+		}
+	}
+
+	public bool IsValid(Vector2I position) => IsValid(position.X, position.Y);
+
+	public bool IsValid(int x, int y) => x >= 0 && x < Width && y >= 0 && y < Height;
+}

src/2024/10/aoc-2024-10.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <RootNamespace>aoc_2024_10</RootNamespace>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\core\core.csproj" />
+  </ItemGroup>
+
+</Project>