2024 day 19 part 1 with my dumbest solution yet

2024/19/example.txt

@@ -0,0 +1,10 @@
+r, wr, b, g, bwu, rb, gb, br
+
+brwrr
+bggr
+gbbr
+rrbgbr
+ubwu
+bwurrg
+brgr
+bbrgwb

2024/19/solution.nix

@@ -0,0 +1,26 @@
+{input ? "", lib, ...}: let
+  inherit (builtins) elemAt filter length;
+
+  exampleIn = lib.readFile ./example.txt;
+  
+  mkSolution = {text}: let
+    parts = text |> lib.trim |> lib.splitString "\n\n";
+    towels = elemAt parts 0 |> lib.splitString ", ";
+    regex = ''(${builtins.concatStringsSep "|" towels})+'';
+    desired = elemAt parts 1 |> lib.splitString "\n";
+    matches = desired |> map (lib.match regex);
+  in {
+    inherit towels regex desired matches;
+    count = matches
+      |> filter (m: !isNull m)
+      |> length;
+  };
+
+in {
+  example = mkSolution {
+    text = exampleIn;
+  };
+  real = mkSolution {
+    text = input;
+  };
+}

2024/flake.lock

@@ -3,8 +3,8 @@
     "aoc-inputs": {
       "flake": false,
       "locked": {
-        "lastModified": 1734543082,
-        "narHash": "sha256-hU8vRkPOKfQqp34Ffx4INiz3l6HdwGcbfyHgqO4qheM=",
+        "lastModified": 1734614378,
+        "narHash": "sha256-vEsmquzc9r82OCVx2Q9WjdND7aOy39Oot3QDJcInhXk=",
         "path": "/tmp/aoc-inputs",
         "type": "path"
       },