advent-of-code/2022/d03/ex2/ex2.py

30 lines
704 B
Python
Executable file

#!/usr/bin/env python
import sys
from collections.abc import Iterator
Group = tuple[str, str, str]
def solve(input: list[str]) -> int:
def score(lines: Group) -> int:
common_items = set(lines[0]) & set(lines[1]) & set(lines[2])
assert len(common_items) == 1 # Sanity check
common = common_items.pop()
return common.isupper() * 26 + ord(common.lower()) - ord("a") + 1
def iter_3() -> Iterator[Group]:
args = [iter(input)] * 3
yield from zip(*args, strict=True) # type: ignore
return sum(map(score, iter_3()))
def main() -> None:
input = sys.stdin.read().splitlines()
print(solve(input))
if __name__ == "__main__":
main()