aoc2024day25.py

# === Parsing ===

keys = []
locks = []

with open("input.txt", "r") as f:
    contents = f.read()
    for block in contents.split("\n\n"):
        lines = block.splitlines()
        counts = [col.count("#") - 1 for col in zip(*lines)]
        if lines[0].count("#") == 0:
            keys.append(counts)
        else:
            locks.append(counts)


# === Part 1 ===
from itertools import product

valid_pairings = 0
for key, lock in product(keys, locks):
    valid_pairings += all(k + l < 6 for k, l in zip(key, lock))
print(valid_pairings)  # 3155


# === Part 2 ===
# SPOILERS AHEAD