day 7

AdventOfCode/Problems/AOC2025/Day7/Laboratories.cs

@@ -1,23 +1,111 @@
-using System;
+using AdventOfCode.Utils.Models;
+
+using MaybeError;
+using MaybeError.Errors;
+
+using System;
 using System.Collections.Generic;
+using System.ComponentModel;
 using System.Text;
 
 namespace AdventOfCode.Problems.AOC2025.Day7;
 [ProblemInfo(2025, 7, "Laboratories")]
 internal class Laboratories : Problem<long, long>
 {
+	private string[] _grid = [];
+	private Vec2<int> _size;
+
 	public override void CalculatePart1()
 	{
-		throw new NotImplementedException();
+		var start = GetStart(_grid).Value;
+		Part1 = TraceBeam(start, _grid, _size);
 	}
 
 	public override void CalculatePart2()
 	{
-		throw new NotImplementedException();
+		var start = GetStart(_grid).Value;
+		Part2 = QuantumTraceBeam(start, _grid, _size, []);
 	}
 
+	private static Maybe<Vec2<int>> GetStart(string[] data)
+	{
+		for (int y = 0; y < data.Length; y++)
+		{
+			var ln = data[y];
+			for (int x = 0; x < ln.Length; x++)
+			{
+				if (ln[x] == 'S')
+					return new Vec2<int>(x, y);
+			}
+		}
+		return new Error("There is no start position");
+	}
+
+	private static long TraceBeam(Vec2<int> pos, string[] data, Vec2<int> size)
+	{
+		return TraceBeam(pos, data, size, []);
+	}
+	private static long TraceBeam(Vec2<int> pos, string[] data, Vec2<int> size, HashSet<Vec2<int>> visited)
+	{
+		if (pos.X < 0 || pos.Y < 0)
+			return 0;
+		if (pos.X >= size.X || pos.Y >= size.Y)
+			return 0;
+		var curPos = data[pos.Y][pos.X];
+
+		if (curPos == '^')
+		{
+			var left = new Vec2<int>(pos.X - 1, pos.Y);
+			var right = new Vec2<int>(pos.X + 1, pos.Y);
+			var leftCount = visited.Add(left) ? TraceBeam(left, data, size, visited) : 0;
+			var rightCount = visited.Add(right) ? TraceBeam(right, data, size, visited) : 0;
+			return 1 + leftCount + rightCount;
+		}
+		var next = new Vec2<int>(pos.X, pos.Y + 1);
+		if (visited.Contains(next))
+			return 0;
+		visited.Add(next);
+		return TraceBeam(next, data, size, visited);
+	}
+
+	private static long QuantumTraceBeam(Vec2<int> pos, string[] data, Vec2<int> size, Dictionary<Vec2<int>, long> trace)
+	{
+
+		if (pos.X < 0 || pos.Y < 0)
+			return 1;
+		if (pos.X >= size.X || pos.Y >= size.Y)
+			return 1;
+		if (trace.TryGetValue(pos, out var c))
+			return c;
+		var curPos = data[pos.Y][pos.X];
+
+		if (curPos == '^')
+		{
+			var left = new Vec2<int>(pos.X - 1, pos.Y);
+			var right = new Vec2<int>(pos.X + 1, pos.Y);
+
+			if (!trace.TryGetValue(left, out long leftCount))
+			{
+				leftCount = QuantumTraceBeam(left, data, size, trace);
+				trace.Add(left, leftCount);
+			}
+
+			if (!trace.TryGetValue(right, out long rightCount))
+			{
+				rightCount = QuantumTraceBeam(right, data, size, trace);
+				trace.Add(right, rightCount);
+			}
+
+			return leftCount + rightCount;
+		}
+		return QuantumTraceBeam(new(pos.X, pos.Y + 1), data, size, trace);
+	}
+
+
+
 	public override void LoadInput()
 	{
-		throw new NotImplementedException();
+		_grid = ReadInputLines("input.txt");
+		_size = new Vec2<int>(_grid[0].Length, _grid.Length);
 	}
 }

AdventOfCode/Utils/Models/Common.cs

@@ -36,6 +36,7 @@ public record struct Vec2<T>(T X, T Y) where T : INumber<T>
 
 	public readonly Vec2<T> Abs() => new(T.Abs(X), T.Abs(Y));
 
+
 	public override readonly string ToString()
 	{
 		return $"({X}, {Y})";