From 46a7e459f67aefde03b6f9f0a5305cd963437870 Mon Sep 17 00:00:00 2001
From: Sebastian Mark <smark@posteo.net>
Date: Wed, 25 Dec 2024 11:23:57 +0100
Subject: [PATCH] add 2024/day25.1

---
 2024/25/main.py | 79 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 2024/25/main.py

diff --git a/2024/25/main.py b/2024/25/main.py
new file mode 100644
index 0000000..63e428c
--- /dev/null
+++ b/2024/25/main.py
@@ -0,0 +1,79 @@
+#!/usr/bin/env python
+# -*- encoding: utf-8; py-indent-offset: 4 -*-
+
+# Author: Sebastian Mark
+# CC-BY-SA (https://creativecommons.org/licenses/by-sa/4.0/deed.de)
+
+# pylint: disable=missing-module-docstring,missing-function-docstring,consider-using-f-string
+
+import re
+
+
+def parse_lock(block: list) -> list:
+    lock = [0] * 5
+    for y, _ in enumerate(block):
+        pins = re.finditer(r"#", block[y])
+        for p in pins:
+            lock[p.start()] = y
+
+    return lock
+
+
+def parse_key(block: list) -> list:
+    key = [0] * 5
+    for y, _ in enumerate(block):
+        pins = re.finditer(r"\.", block[y])
+        for p in pins:
+            key[p.start()] = len(block) - 2 - y
+
+    return key
+
+
+def readinput():
+    with open("input", "r", encoding="utf-8") as file:
+        schematics = []
+        current_schematic = []
+
+        for line in file:
+            line = line.rstrip()
+            if line:
+                current_schematic.append(line)
+            else:
+                schematics.append(current_schematic)
+                current_schematic = []
+
+        schematics.append(current_schematic)
+
+    keys = []
+    locks = []
+    for schematic in schematics:
+        if schematic[0] == "#####":
+            locks.append(parse_lock(schematic))
+        else:
+            keys.append(parse_key(schematic))
+
+    return keys, locks
+
+
+def key_fits_lock(key: list, lock: list) -> bool:
+    for k, l in zip(key, lock):
+        if k + l >= 6:
+            return False
+    return True
+
+
+def main():
+    keys, locks = readinput()
+
+    # part 1
+    fitting = 0
+    for key in keys:
+        for lock in locks:
+            if key_fits_lock(key, lock):
+                fitting += 1
+
+    print("Fitting keys: %d" % fitting)
+
+
+if __name__ == "__main__":
+    main()