advent-of-code/2021/d10/ex1/ex1.py

52 lines
1.1 KiB
Python
Executable file

#!/usr/bin/env python
import itertools
import sys
from typing import List, Optional, cast
def solve(input: List[str]) -> int:
def find_illegal_char(input: str) -> Optional[int]:
chunks: List[str] = []
ends_to_start = {
")": "(",
"]": "[",
"}": "{",
">": "<",
}
for i, c in enumerate(input):
# Is it a chunk beginning
if c not in ends_to_start:
chunks.append(c)
continue
# Is it matching the last element on the chunk stack
current = chunks.pop()
# If not, corruption has been found
if ends_to_start[c] != current:
return i
return None
score = {
")": 3,
"]": 57,
"}": 1197,
">": 25137,
}
return sum(
score[line[cast(int, find_illegal_char(line))]]
for line in input
if find_illegal_char(line) is not None
)
def main() -> None:
input = [line.strip() for line in sys.stdin.readlines()]
print(solve(input))
if __name__ == "__main__":
main()