feat: solve part 1
This commit is contained in:
Stevan Freeborn
+372
-2
@@ -1,2 +1,372 @@
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// See https://aka.ms/new-console-template for more information
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Console.WriteLine("Hello, World!");
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using System.Diagnostics;
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namespace PipeMaze;
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public class Program
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{
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public static async Task<int> Main(string[] args)
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{
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if (args.Length is 0)
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{
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Console.WriteLine("Please provide a path to the input file.");
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return -1;
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}
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if (File.Exists(args[0]) is false)
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{
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Console.WriteLine("The provided file does not exist.");
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return -2;
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}
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var input = await File.ReadAllLinesAsync(args[0]);
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var stopwatch = new Stopwatch();
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stopwatch.Start();
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var result = Maze.Parse(input).FarthestStepFromStart;
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stopwatch.Stop();
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Console.WriteLine($"The farthest step from the starting pipe is {result}. ({stopwatch.ElapsedMilliseconds}ms)");
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return result;
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}
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}
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public class Maze(
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int width,
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int height,
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List<Pipe> pipes
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)
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{
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private static readonly Dictionary<char, PipeType> _pipes = new()
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{
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{ '|', PipeType.UpAndDown },
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{ '-', PipeType.LeftAndRight },
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{ 'L', PipeType.UpAndRight },
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{ 'J', PipeType.UpAndLeft },
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{ '7', PipeType.DownAndLeft },
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{ 'F', PipeType.DownAndRight },
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{ 'S', PipeType.Unknown },
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};
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public int Width { get; init; } = width;
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public int Height { get; init; } = height;
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public List<Pipe> Pipes { get; init; } = pipes;
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public Pipe? StartingPipe => Pipes.FirstOrDefault(p => p.Type is PipeType.Unknown);
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public int FarthestStepFromStart => GetLoop().Count / 2;
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public List<Pipe> GetLoop()
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{
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if (StartingPipe is null)
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{
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return [];
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}
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var loop = new List<Pipe>();
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var startingPipeType = IdentifyStartPipeType();
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var currentPipe = new Pipe(
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StartingPipe.Symbol,
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startingPipeType,
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StartingPipe.Coordinate.Row,
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StartingPipe.Coordinate.Column
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);
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do
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{
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loop.Add(currentPipe);
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var connectingPipes = GetConnectingPipes(currentPipe);
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currentPipe = connectingPipes
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.FirstOrDefault(
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p =>
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p is not null &&
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loop.Any(pipe => pipe.Coordinate.Equals(p.Coordinate)) is false
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);
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} while (currentPipe?.Equals(StartingPipe) is false);
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return loop;
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}
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public PipeType IdentifyStartPipeType()
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{
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if (StartingPipe is null)
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{
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return PipeType.Unknown;
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}
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var connectingPipes = GetConnectingPipes(StartingPipe);
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var pipeAbove = connectingPipes.FirstOrDefault(p => p?.Coordinate.Row < StartingPipe.Coordinate.Row);
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var pipeBelow = connectingPipes.FirstOrDefault(p => p?.Coordinate.Row > StartingPipe.Coordinate.Row);
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var pipeToTheLeft = connectingPipes.FirstOrDefault(p => p?.Coordinate.Column < StartingPipe.Coordinate.Column);
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var pipeToTheRight = connectingPipes.FirstOrDefault(p => p?.Coordinate.Column > StartingPipe.Coordinate.Column);
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var isPipeAboveConnected = pipeAbove is not null &&
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pipeAbove.Type is PipeType.UpAndDown or PipeType.DownAndRight or PipeType.DownAndLeft;
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var isPipeBelowConnected = pipeBelow is not null &&
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pipeBelow.Type is PipeType.UpAndDown or PipeType.UpAndRight or PipeType.UpAndLeft;
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var isPipeToTheLeftConnected = pipeToTheLeft is not null &&
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pipeToTheLeft.Type is PipeType.LeftAndRight or PipeType.DownAndRight or PipeType.UpAndRight;
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var isPipeToTheRightConnected = pipeToTheRight is not null &&
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pipeToTheRight.Type is PipeType.LeftAndRight or PipeType.DownAndLeft or PipeType.UpAndLeft;
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if (isPipeAboveConnected && isPipeBelowConnected && isPipeToTheLeftConnected && isPipeToTheRightConnected)
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{
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return PipeType.Unknown;
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}
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if (isPipeAboveConnected && isPipeBelowConnected)
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{
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return PipeType.UpAndDown;
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}
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if (isPipeToTheLeftConnected && isPipeToTheRightConnected)
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{
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return PipeType.LeftAndRight;
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}
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if (isPipeAboveConnected && isPipeToTheRightConnected)
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{
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return PipeType.UpAndRight;
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}
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if (isPipeAboveConnected && isPipeToTheLeftConnected)
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{
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return PipeType.UpAndLeft;
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}
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if (isPipeBelowConnected && isPipeToTheRightConnected)
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{
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return PipeType.DownAndRight;
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}
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if (isPipeBelowConnected && isPipeToTheLeftConnected)
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{
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return PipeType.DownAndLeft;
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}
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return PipeType.Unknown;
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}
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public List<Pipe?> GetConnectingPipes(Pipe pipe)
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{
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var connectingPipes = new List<Pipe?>();
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var isNotOnFirstRow = pipe.Coordinate.Row > 0;
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var isNotOnFirstColumn = pipe.Coordinate.Column > 0;
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var isNotOnLastRow = pipe.Coordinate.Row < Height - 1;
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var isNotOnLastColumn = pipe.Coordinate.Column < Width - 1;
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switch (pipe.Type)
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{
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case PipeType.UpAndDown:
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{
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if (isNotOnFirstRow)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column && p.Coordinate.Row == pipe.Coordinate.Row - 1)
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);
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}
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if (isNotOnLastRow)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column && p.Coordinate.Row == pipe.Coordinate.Row + 1)
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);
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}
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break;
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}
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case PipeType.LeftAndRight:
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{
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if (isNotOnFirstColumn)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column - 1 && p.Coordinate.Row == pipe.Coordinate.Row)
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);
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}
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if (isNotOnLastColumn)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column + 1 && p.Coordinate.Row == pipe.Coordinate.Row)
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);
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}
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break;
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}
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case PipeType.UpAndRight:
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{
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if (isNotOnFirstRow)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column && p.Coordinate.Row == pipe.Coordinate.Row - 1)
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);
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}
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if (isNotOnLastColumn)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column + 1 && p.Coordinate.Row == pipe.Coordinate.Row)
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);
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}
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break;
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}
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case PipeType.UpAndLeft:
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{
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if (isNotOnFirstRow)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column && p.Coordinate.Row == pipe.Coordinate.Row - 1)
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);
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}
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if (isNotOnFirstColumn)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column - 1 && p.Coordinate.Row == pipe.Coordinate.Row)
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);
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}
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break;
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}
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case PipeType.DownAndRight:
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{
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if (isNotOnLastRow)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column && p.Coordinate.Row == pipe.Coordinate.Row + 1)
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);
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}
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if (isNotOnLastColumn)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column + 1 && p.Coordinate.Row == pipe.Coordinate.Row)
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);
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}
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break;
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}
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case PipeType.DownAndLeft:
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{
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if (isNotOnLastRow)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column && p.Coordinate.Row == pipe.Coordinate.Row + 1)
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);
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}
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if (isNotOnFirstColumn)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column - 1 && p.Coordinate.Row == pipe.Coordinate.Row)
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);
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}
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break;
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}
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case PipeType.Unknown:
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{
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if (isNotOnFirstRow)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column && p.Coordinate.Row == pipe.Coordinate.Row - 1)
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);
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}
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if (isNotOnLastColumn)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column + 1 && p.Coordinate.Row == pipe.Coordinate.Row)
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);
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}
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if (isNotOnLastRow)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column && p.Coordinate.Row == pipe.Coordinate.Row + 1)
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);
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}
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if (isNotOnFirstColumn)
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{
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connectingPipes.Add(
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Pipes.FirstOrDefault(p => p.Coordinate.Column == pipe.Coordinate.Column - 1 && p.Coordinate.Row == pipe.Coordinate.Row)
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);
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}
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break;
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}
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default:
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break;
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}
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return connectingPipes;
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}
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public static Maze Parse(string[] input)
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{
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var width = input[0].Length;
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var height = input.Length;
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var pipes = new List<Pipe>();
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for (var row = 0; row < height; row++)
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{
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for (var column = 0; column < width; column++)
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{
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var symbol = input[row][column];
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if (_pipes.TryGetValue(symbol, out PipeType value))
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{
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pipes.Add(new(symbol, value, row, column));
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}
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}
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}
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return new Maze(width, height, pipes);
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}
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}
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public class Pipe(
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char symbol,
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PipeType type,
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int row,
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int column
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)
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{
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public char Symbol { get; init; } = symbol;
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public PipeType Type { get; init; } = type;
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public PipeCoordinate Coordinate { get; init; } = new(column, row);
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}
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public class PipeCoordinate(
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int column,
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int row
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) : IEquatable<PipeCoordinate>
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{
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public int Column { get; init; } = column;
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public int Row { get; init; } = row;
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public bool Equals(PipeCoordinate? other) =>
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other is not null &&
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Column == other.Column &&
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Row == other.Row;
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}
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public enum PipeType
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{
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UpAndDown, // Vertical Pipe
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LeftAndRight, // Horizontal Pipe
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UpAndRight, // North-East Pipe
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UpAndLeft, // North-West Pipe
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DownAndRight, // South-East Pipe
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DownAndLeft, // South-West Pipe
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Unknown, // Starting Pipe
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}
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Reference in New Issue
Block a user