12

Author: encse

2025/Day12/Solution.cs

@@ -3,35 +3,15 @@ namespace AdventOfCode.Y2025.Day12;
 using System;
 using System.Linq;
 using System.Text.RegularExpressions;
-record Todo(int w, int h, int[] counts);
 
 [ProblemName("Christmas Tree Farm")]
 class Solution : Solver {
 
     public object PartOne(string input) {
-        // 🎄 🎄 🎄 This problem was a joke by Eric. The solution is specific to the input.
-        
-        var blocks = input.Split("\n\n");
-
-        var areas = (
-            from block in blocks[..^1]
-            let area = block.Count(ch => ch == '#')
-            select area
-        ).ToArray();
-
-        var todos = (
-            from line in blocks.Last().Split("\n")
-            let nums = Regex.Matches(line, @"\d+").Select(m => int.Parse(m.Value)).ToArray()
-            select new Todo(nums[0], nums[1], nums[2..])
-        ).ToArray();
-       
-        var res = 0;
-        foreach(var todo in todos) {
-            var areaNeeded = Enumerable.Zip(todo.counts, areas).Sum(p => p.First * p.Second);
-            if (areaNeeded <= todo.w * todo.h) {
-                res++;
-            }
-        }
-        return res;
+        // 🎄 🎄 🎄 This problem was a joke by Eric. The solution is input specific.
+        return input.Split("\n\n").Last()
+            .Split("\n")
+            .Select(line => Regex.Matches(line, @"\d+").Select(m => int.Parse(m.Value)).ToArray())
+            .Count(nums => nums[0] * nums[1] >= 9 * nums[2..].Sum());
     }
 }