From c84a4e8ffe01be91eddab9960421f3e3e3524b89 Mon Sep 17 00:00:00 2001
From: Amatsugu <khamraj@kaisei.app>
Date: Thu, 21 Dec 2023 22:24:46 -0500
Subject: [PATCH] day 12 wip

---
 AdventOfCode/AdventOfCode.csproj              |   1 +
 .../Problems/AOC2023/Day12/HotSprings.cs      | 104 ++++++++++++++++++
 2 files changed, 105 insertions(+)
 create mode 100644 AdventOfCode/Problems/AOC2023/Day12/HotSprings.cs

diff --git a/AdventOfCode/AdventOfCode.csproj b/AdventOfCode/AdventOfCode.csproj
index a80df42..b34d532 100644
--- a/AdventOfCode/AdventOfCode.csproj
+++ b/AdventOfCode/AdventOfCode.csproj
@@ -45,6 +45,7 @@
 	<None Remove="problems\aoc2023\day10\sample.txt" />
 	<None Remove="problems\aoc2023\day11\input.txt" />
 	<None Remove="problems\aoc2023\day11\sample.txt" />
+	<None Remove="problems\aoc2023\day12\sample.txt" />
 	<None Remove="problems\aoc2023\day1\input.txt" />
 	<None Remove="problems\aoc2023\day2\input.txt" />
 	<None Remove="problems\aoc2023\day3\input.txt" />
diff --git a/AdventOfCode/Problems/AOC2023/Day12/HotSprings.cs b/AdventOfCode/Problems/AOC2023/Day12/HotSprings.cs
new file mode 100644
index 0000000..ebaf0e7
--- /dev/null
+++ b/AdventOfCode/Problems/AOC2023/Day12/HotSprings.cs
@@ -0,0 +1,104 @@
+using AdventOfCode.Runner.Attributes;
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace AdventOfCode.Problems.AOC2023.Day12;
+
+[ProblemInfo(2023, 12, "Hot Springs")]
+internal class HotSprings : Problem<int, int>
+{
+	private Record[] _data = [];
+
+	public override void CalculatePart1()
+	{
+		Console.WriteLine();
+		Console.WriteLine(Record.CheckValidity(new Record(".###...##...", [3,2,1])));
+		
+		var a = CountPossiblilites(_data[5]);
+	}
+
+	public override void CalculatePart2()
+	{
+		throw new NotImplementedException();
+	}
+
+	public int CountPossiblilites(Record record, int pos = 0)
+	{
+		if(!record.Data.Contains('?'))
+			Console.WriteLine(record);
+		if (pos == -1 || pos >= record.Data.Length)
+			return record.IsValid ? 1 : 0;
+		if (!record.IsValid)
+			return 0;
+		if (record.Data[pos] != '?')
+			return CountPossiblilites(record, record.Data.IndexOf('?'));
+
+		var front = record.Data[..pos];
+		var back = record.Data[(pos + 1)..];
+		var r1 = record with { Data = $"{front}.{back}" };
+		var r2 = record with { Data = $"{front}#{back}" };
+		return CountPossiblilites(r1, pos + 1) + CountPossiblilites(r2, pos + 1);
+	}
+
+	
+
+	public override void LoadInput()
+	{
+		var data = ReadInputLines("sample.txt");
+
+		_data = data.Select(x => x.Split(' '))
+			.Select(x => new Record(x[0], x[1].Split(',').Select(int.Parse).ToArray()))
+			.ToArray();
+	}
+
+
+	public record Record(string Data, int[] Pattern)
+	{
+		public bool IsValid => CheckValidity(this);
+		public static bool CheckValidity(Record record)
+		{
+			var section = 0;
+			var start = 0;
+			var inSection = false;
+			for (int i = 0; i < record.Data.Length; i++)
+			{
+				var c = record.Data[i];
+				var len = section >= record.Pattern.Length - 1 ? -1 : record.Pattern[section];
+
+				switch (c)
+				{
+					case '?':
+						if (inSection && i - start > len)
+							return false;
+						return true;
+					case '.':
+						if (inSection)
+						{
+							if (i - start != len)
+								return false;
+							inSection = false;
+							start = 0;
+							section++;
+						}
+						continue;
+					case '#':
+						if (!inSection)
+						{
+							inSection = true;
+							start = i;
+						}
+						break;
+				}
+			}
+			if (section != record.Pattern.Length)
+				return false;
+			if (inSection && record.Pattern[section] < (record.Data.Length - 1 - start))
+				return false;
+			return true;
+		}
+	};
+}