Merge pull request #11 from StevanFreeborn/stevanfreeborn/feat/solve-puzzle-11

feat: solve puzzle 11

11/CosmicExpansion.Tests/CosmicExpansion.Tests.csproj

@@ -0,0 +1,36 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="FluentAssertions" Version="6.12.0" />
+    <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>
+    <PackageReference Include="coverlet.collector" Version="6.0.0">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\CosmicExpansion\CosmicExpansion.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Content Include="..\INPUT.txt">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+
+</Project>

11/CosmicExpansion.Tests/GlobalUsings.cs

@@ -0,0 +1,2 @@
+global using Xunit;
+global using FluentAssertions;

11/CosmicExpansion.Tests/UniverseTests.cs

@@ -0,0 +1,143 @@
+namespace CosmicExpansion.Tests;
+
+public class UniverseTests
+{
+  [Theory]
+  [MemberData(nameof(TestData.ParseTestData), MemberType = typeof(TestData))]
+  public void Parse_WhenGivenUniverseWithGalaxies_ItShouldReturnListOfGalaxies(string[] givenInput, Universe expectedUniverse)
+  {
+    var result = Universe.Parse(givenInput);
+    result.Should().BeEquivalentTo(expectedUniverse);
+  }
+
+  [Theory]
+  [MemberData(nameof(TestData.GetShortestPathsBetweenGalaxiesTestData), MemberType = typeof(TestData))]
+  public void GetShortestPathsBetweenGalaxies_WhenGivenUniverseWithGalaxies_ItShouldReturnShortestPathsBetweenGalaxies(Universe givenUniverse, int expectedNumberOrPaths)
+  {
+    var result = givenUniverse.GetShortestPathsBetweenGalaxies();
+    result.Count.Should().Be(expectedNumberOrPaths);
+  }
+
+  [Theory]
+  [MemberData(nameof(TestData.SumOfShortestPathsBetweenGalaxiesTestData), MemberType = typeof(TestData))]
+  public void SumOfShortestPathsBetweenGalaxies_WhenGivenUniverseWithGalaxies_ItShouldReturnSumOfShortestPathsBetweenGalaxies(Universe givenUniverse, int expectedSumOfShortestPaths)
+  {
+    givenUniverse.SumOfShortestPathsBetweenGalaxies.Should().Be(expectedSumOfShortestPaths);
+  }
+
+  [Theory]
+  [MemberData(nameof(TestData.CalculateDistanceBetweenGalaxiesTestData), MemberType = typeof(TestData))]
+  public void CalculateDistanceBetweenGalaxies_WhenGivenTwoGalaxies_ItShouldReturnDistanceBetweenGalaxies(Galaxy startGalaxy, Galaxy endGalaxy, int expectedDistance)
+  {
+    var result = Universe.CalculateDistanceBetweenGalaxies(startGalaxy, endGalaxy);
+    result.Should().Be(expectedDistance);
+  }
+
+  [Fact]
+  public void SumOfShortestPathsBetweenGalaxies_WhenGivenInput_ItShouldReturnSumOfShortestPathsBetweenGalaxies()
+  {
+    var input = File.ReadAllLines("INPUT.txt");
+    var universe = Universe.Parse(input);
+    universe.SumOfShortestPathsBetweenGalaxies.Should().Be(10292708);
+  }
+
+  [Fact]
+  public void SumOfShortestPathsBetweenGalaxies_WhenGivenInputAndIsPart2_ItShouldReturnSumOfShortestPathsBetweenGalaxies()
+  {
+    var input = File.ReadAllLines("INPUT.txt");
+    var universe = Universe.Parse(input, 1_000_000);
+    universe.SumOfShortestPathsBetweenGalaxies.Should().Be(790194712336);
+  }
+
+
+
+  public static class TestData
+  {
+    private static readonly Universe TestUniverse = new(
+      12,
+      13,
+      [
+        new(0, 4),
+        new(1, 9),
+        new(2, 0),
+        new(5, 8),
+        new(6, 1),
+        new(7, 12),
+        new(10, 9),
+        new(11, 0),
+        new(11, 5),
+      ]
+    );
+
+    public static IEnumerable<object[]> ParseTestData =>
+      new List<object[]>
+      {
+        new object[]
+        {
+          new string[]
+          {
+            "...#......",
+            ".......#..",
+            "#.........",
+            "..........",
+            "......#...",
+            ".#........",
+            ".........#",
+            "..........",
+            ".......#..",
+            "#...#.....",
+          },
+          TestUniverse,
+        }
+      };
+
+    public static IEnumerable<object[]> GetShortestPathsBetweenGalaxiesTestData =>
+      new List<object[]>
+      {
+        new object[]
+        {
+          TestUniverse,
+          36,
+        }
+      };
+
+    public static IEnumerable<object[]> SumOfShortestPathsBetweenGalaxiesTestData =>
+      new List<object[]>
+      {
+        new object[]
+        {
+          TestUniverse,
+          374,
+        }
+      };
+
+    public static IEnumerable<object[]> CalculateDistanceBetweenGalaxiesTestData =>
+      new List<object[]>
+      {
+        new object[]
+        {
+          TestUniverse.Galaxies[4],
+          TestUniverse.Galaxies[8],
+          9,
+        },
+        new object[]
+        {
+          TestUniverse.Galaxies[0],
+          TestUniverse.Galaxies[6],
+          15,
+        },
+        new object[]
+        {
+          TestUniverse.Galaxies[2],
+          TestUniverse.Galaxies[5],
+          17,
+        },
+        new object[]
+        {
+          TestUniverse.Galaxies[7],
+          TestUniverse.Galaxies[8],
+          5,
+        }
+      };
+  }
+}

11/CosmicExpansion/CosmicExpansion.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

11/CosmicExpansion/Program.cs

@@ -0,0 +1,223 @@
+using System.Diagnostics;
+
+namespace CosmicExpansion;
+
+public class Program
+{
+  public static async Task<int> Main(string[] args)
+  {
+    if (args.Length is 0)
+    {
+      Console.WriteLine("Please provide a path to the input file.");
+      return -1;
+    }
+
+    if (File.Exists(args[0]) is false)
+    {
+      Console.WriteLine("The provided file does not exist.");
+      return -2;
+    }
+
+    var isPart2 = args.Length > 1 && args[1] == "part2";
+    var input = await File.ReadAllLinesAsync(args[0]);
+
+    var stopwatch = new Stopwatch();
+    stopwatch.Start();
+
+    var universe = isPart2
+      ? Universe.Parse(input, 1_000_000)
+      : Universe.Parse(input);
+
+    var result = universe.SumOfShortestPathsBetweenGalaxies;
+
+    stopwatch.Stop();
+
+    Console.WriteLine($"The sum of the shortest paths between galaxies is {result}. ({stopwatch.ElapsedMilliseconds}ms)");
+
+    return (int)result;
+  }
+}
+
+/// <summary>
+/// Represents the universe.
+/// </summary>
+/// <param name="Height">The height of the universe.</param>
+/// <param name="Width">The width of the universe.</param>
+/// <param name="Galaxies">The galaxies in the universe.</param>
+/// <returns>An instance of <see cref="Universe"/>.</returns>
+public class Universe(
+  int height,
+  int width,
+  List<Galaxy> galaxies
+)
+{
+  private const char GalaxySymbol = '#';
+
+  /// <summary>
+  /// Gets the height of the universe.
+  /// </summary>
+  public int Height { get; init; } = height;
+
+  /// <summary>
+  /// Gets the width of the universe.
+  /// </summary>
+  public int Width { get; init; } = width;
+
+  /// <summary>
+  /// Gets the galaxies in the universe.
+  /// </summary>
+  public List<Galaxy> Galaxies { get; init; } = galaxies;
+
+  /// <summary>
+  /// Gets the sum of the shortest paths between galaxies.
+  /// </summary>
+  public long SumOfShortestPathsBetweenGalaxies =>
+    GetShortestPathsBetweenGalaxies()
+    .Values
+    .Sum();
+
+  /// <summary>
+  /// Gets the shortest paths between all pairs of galaxies.
+  /// </summary>
+  /// <returns>A dictionary containing the shortest paths between galaxies.</returns>
+  public Dictionary<(int galaxyOneIndex, int galaxyTwoIndex), long> GetShortestPathsBetweenGalaxies()
+  {
+    var shortestPaths = new Dictionary<(int galaxyOneIndex, int galaxyTwoIndex), long>();
+
+    for (int i = 0; i < Galaxies.Count; i++)
+    {
+      var galaxyOne = Galaxies[i];
+
+      for (int j = i + 1; j < Galaxies.Count; j++)
+      {
+        var galaxyTwo = Galaxies[j];
+
+        if (shortestPaths.ContainsKey((i, j)) || shortestPaths.ContainsKey((j, i)))
+        {
+          continue;
+        }
+
+        var shortestPath = CalculateDistanceBetweenGalaxies(galaxyOne, galaxyTwo);
+        shortestPaths.Add((i, j), shortestPath);
+      }
+    }
+
+    return shortestPaths;
+  }
+
+  /// <summary>
+  /// Calculates the distance between two galaxies.
+  /// </summary>
+  /// <param name="galaxyOne">The first galaxy.</param>
+  /// <param name="galaxyTwo">The second galaxy.</param>
+  /// <returns>The distance between the two galaxies.</returns>
+  public static long CalculateDistanceBetweenGalaxies(Galaxy galaxyOne, Galaxy galaxyTwo) =>
+    Math.Abs(galaxyTwo.Row - galaxyOne.Row) + Math.Abs(galaxyTwo.Column - galaxyOne.Column);
+
+  /// <summary>
+  /// Parses the input into an instance of <see cref="Universe"/>.
+  /// </summary>
+  /// <param name="input">The input.</param>
+  /// <param name="expandFactor">The factor by which to expand the universe.</param>
+  /// <returns>An instance of <see cref="Universe"/>.</returns>
+  public static Universe Parse(string[] input, int expandFactor = 2)
+  {
+    var emptyRows = new List<int>();
+    var emptyColumns = new List<int>();
+    var galaxies = new List<Galaxy>();
+
+    for (int i = 0; i < input.Length; i++)
+    {
+      var currentRow = input[i];
+
+      if (currentRow.Contains(GalaxySymbol) is false)
+      {
+        emptyRows.Add(i);
+      }
+    }
+
+    for (int i = 0; i < input[0].Length; i++)
+    {
+      var galaxyInColumn = false;
+
+      for (int j = 0; j < input.Length; j++)
+      {
+        var currentPosition = input[j][i];
+
+        if (currentPosition == GalaxySymbol)
+        {
+          galaxyInColumn = true;
+          break;
+        }
+      }
+
+      if (galaxyInColumn is false)
+      {
+        emptyColumns.Add(i);
+      }
+    }
+
+    for (int i = 0; i < input.Length; i++)
+    {
+      var currentRow = input[i];
+
+      for (int j = 0; j < currentRow.Length; j++)
+      {
+        var currentPosition = currentRow[j];
+
+        if (currentPosition == GalaxySymbol)
+        {
+          var numOfEmptyRowsBefore = emptyRows.Where(row => row < i).Count();
+          var rowOffset = numOfEmptyRowsBefore is 0
+            ? 0
+            : (numOfEmptyRowsBefore * expandFactor) - numOfEmptyRowsBefore;
+
+          var numOfEmptyColumnsBefore = emptyColumns.Where(column => column < j).Count();
+          var columnOffset = numOfEmptyColumnsBefore is 0
+            ? 0
+            : (numOfEmptyColumnsBefore * expandFactor) - numOfEmptyColumnsBefore;
+
+          galaxies.Add(new Galaxy(i + rowOffset, j + columnOffset));
+        }
+      }
+    }
+
+    var heightOffset = emptyRows.Count is 0
+      ? 0
+      : (emptyRows.Count * expandFactor) - emptyRows.Count;
+    var widthOffset = emptyColumns.Count is 0
+      ? 0
+      : (emptyColumns.Count * expandFactor) - emptyColumns.Count;
+
+    var height = input.Length + heightOffset;
+    var width = input[0].Length + widthOffset;
+
+    return new Universe(
+      height,
+      width,
+      galaxies
+    );
+  }
+}
+
+/// <summary>
+/// Represents a galaxy.
+/// </summary>
+/// <param name="Row">The row of the galaxy.</param>
+/// <param name="Column">The column of the galaxy.</param>
+/// <returns>An instance of <see cref="Galaxy"/>.</returns>
+public class Galaxy(
+  long row,
+  long column
+)
+{
+  /// <summary>
+  /// Gets the row of the galaxy.
+  /// </summary>
+  public long Row { get; init; } = row;
+
+  /// <summary>
+  /// Gets the column of the galaxy.
+  /// </summary>
+  public long Column { get; init; } = column;
+}

AdventOfCode2023.sln

@@ -63,6 +63,12 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PipeMaze", "10\PipeMaze\Pip
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PipeMaze.Tests", "10\PipeMaze.Tests\PipeMaze.Tests.csproj", "{B1DA407F-DA29-4BDA-B10E-8B9A976B0C5E}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "11", "11", "{01A6D73F-996E-48B3-B111-2725016A49C2}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CosmicExpansion", "11\CosmicExpansion\CosmicExpansion.csproj", "{580A3C98-7A39-4323-839A-5C2E0B6E8E74}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CosmicExpansion.Tests", "11\CosmicExpansion.Tests\CosmicExpansion.Tests.csproj", "{0D6CD658-65BB-47DC-A865-E3428EBE3075}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -152,6 +158,14 @@ Global
 		{B1DA407F-DA29-4BDA-B10E-8B9A976B0C5E}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{B1DA407F-DA29-4BDA-B10E-8B9A976B0C5E}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{B1DA407F-DA29-4BDA-B10E-8B9A976B0C5E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{580A3C98-7A39-4323-839A-5C2E0B6E8E74}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{580A3C98-7A39-4323-839A-5C2E0B6E8E74}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{580A3C98-7A39-4323-839A-5C2E0B6E8E74}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{580A3C98-7A39-4323-839A-5C2E0B6E8E74}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0D6CD658-65BB-47DC-A865-E3428EBE3075}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0D6CD658-65BB-47DC-A865-E3428EBE3075}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0D6CD658-65BB-47DC-A865-E3428EBE3075}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0D6CD658-65BB-47DC-A865-E3428EBE3075}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{3F8EAC09-4BC7-43AA-B72B-48DDD2710F6D} = {8C29858C-623A-461A-BF0B-254E151CD9C2}
@@ -174,5 +188,7 @@ Global
 		{5C39C115-ACBF-458A-9409-FBD23637A789} = {79203C8D-F382-4C95-90EA-FECEE65602DA}
 		{B46ADCFF-35FF-496D-A035-FE2B9FFC185A} = {9703A36A-A019-4ADC-93A7-9DF4EFBCBFBC}
 		{B1DA407F-DA29-4BDA-B10E-8B9A976B0C5E} = {9703A36A-A019-4ADC-93A7-9DF4EFBCBFBC}
+		{580A3C98-7A39-4323-839A-5C2E0B6E8E74} = {01A6D73F-996E-48B3-B111-2725016A49C2}
+		{0D6CD658-65BB-47DC-A865-E3428EBE3075} = {01A6D73F-996E-48B3-B111-2725016A49C2}
 	EndGlobalSection
 EndGlobal

README.md

@@ -54,7 +54,7 @@ dotnet build
 | 08  | [Problem](./08/PROBLEM.md) | [Solution](./08/HauntedWasteland/)  |   ✅   | Got to implement a least common multiple algorithm for part 2.                                                                                   |
 | 09  | [Problem](./09/PROBLEM.md) | [Solution](./09/MirageMaintenance/) |   ✅   | Part 1 took me unnecessarily long. The bug was summing a line to check for all zeros is bad idea when negative numbers are involved.             |
 | 10  | [Problem](./10/PROBLEM.md) |     [Solution](./10/PipeMaze/)      |   ✅   | So...my solutions are rather slow, but they work. Part 2 appears to have a mathematical solution, but scanning is what I came up with on my own. |
-| 11  | [Problem](./11/PROBLEM.md) |          [Solution](./11/)          |   ⌛   |
+| 11  | [Problem](./11/PROBLEM.md) |  [Solution](./11/CosmicExpansion/)  |   ✅   | Expanding the universe was fine in part 1, but part 2 showed I actually needed to calculate the expansion instead of expanding the input.        |
 | 12  | [Problem](./12/PROBLEM.md) |          [Solution](./12/)          |   ⌛   |
 | 13  | [Problem](./13/PROBLEM.md) |          [Solution](./13/)          |   ⌛   |
 | 14  | [Problem](./14/PROBLEM.md) |          [Solution](./14/)          |   ⌛   |