Day 2

AdventOfCode/Problems/AOC2024/Day1/HistorianHysteria.cs

@@ -32,7 +32,7 @@ internal class HistorianHysteria : Problem<int, int>
 
 	public override void LoadInput()
 	{
-		var lines = ReadInputLines("input.txt");
+		var lines = ReadInputLines();
 		var data = lines.Select(l => l.Split(' ').Select(int.Parse)).ToList();
 		_left = data.Select(l => l.First()).ToArray();
 		_right = data.Select(l => l.Last()).ToArray();

AdventOfCode/Problems/AOC2024/Day2/RedNosedReports.cs

@@ -0,0 +1,108 @@
+using AdventOfCode.Runner.Attributes;
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace AdventOfCode.Problems.AOC2024.Day2;
+[ProblemInfo(2024, 2, "Red-Nosed Reports")]
+internal class RedNosedReports : Problem<int, int>
+{
+	private int[][] _data = [];
+
+	private static bool CheckIncrease(int l) => l >= 1 && l <= 3;
+	private static bool CheckDecrease(int l) => l <= -1 && l >= -3;
+
+	public override void CalculatePart1()
+	{
+		var reportAnalysis = Analyze();
+		var increasing = reportAnalysis.Count(r => r.All(CheckIncrease));
+		var decreasing = reportAnalysis.Count(r => r.All(CheckDecrease));
+		Part1 = increasing + decreasing;
+	}
+
+	public override void CalculatePart2()
+	{
+		//Missing 3
+		Console.WriteLine();
+		foreach (var report in _data)
+		{
+			if (CheckSafety(report, out _))
+				Part2++;
+		}
+	}
+
+	private static bool CheckSafety(int[] report, out bool increase)
+	{
+		increase = false;
+		var inFail = Check(report, CheckIncrease);
+		var deFail = Check(report, CheckDecrease);
+
+		if(inFail.Count == 0)
+		{
+			increase = true;
+			return true;
+		}
+		else
+		{
+			if (inFail.Count < report.Length && RemoveFails(report, inFail).Any(g => Check(g, CheckIncrease).Count == 0))
+			{
+				increase = true;
+				return true;
+			}
+		}
+		if(deFail.Count == 0)
+			return true;
+		else
+		{
+			if (deFail.Count < report.Length && RemoveFails(report, deFail).Any(g => Check(g, CheckDecrease).Count == 0))
+				return true;
+		}
+		return false;
+	}
+
+	static int[][] RemoveFails(int[] report, List<int> fails)
+	{
+		var results = new int[fails.Count][];
+		for (int i = 0; i < fails.Count; i++)
+		{
+			var f = fails[i];
+			results[i] = f == 0 ? report[1..] : f == report.Length-1 ? report[..^1] : [.. report[..f], .. report[(f+1)..]];
+		}
+		return results;
+	}
+
+	static List<int> Check(int[] report, Func<int, bool> check)
+	{
+		var fails = new List<int>();
+		for (int i = 1; i < report.Length; i++)
+		{
+			var d = report[i] - report[i-1];
+			if (!check(d))
+				fails.AddRange([i, i-1]);
+		}
+
+		return fails.Distinct().ToList();
+	}
+
+	private int[][] Analyze()
+	{
+		var reportAnalysis = new int[_data.Length][];
+		for (int ridx = 0; ridx < _data.Length; ridx++)
+		{
+			int[]? report = _data[ridx];
+			var safety = new int[report.Length - 1];
+			for (int i = 1; i < report.Length; i++)
+				safety[i - 1] = report[i] - report[i - 1];
+			reportAnalysis[ridx] = safety;
+		}
+		return reportAnalysis;
+	}
+
+	public override void LoadInput()
+	{
+		_data = ReadInputLines("input.txt").Select(l => l.Split(' ').Select(int.Parse).ToArray()).ToArray();
+	}
+}