advent-of-code/2020/d02/ex1/ex1.py

43 lines
808 B
Python
Executable file

#!/usr/bin/env python
import re
import sys
from dataclasses import dataclass
from typing import List
@dataclass
class Policy:
min: int
max: int
letter: str
@dataclass
class Password:
policy: Policy
password: str
def is_valid(pwd: Password) -> bool:
occurences = pwd.password.count(pwd.policy.letter)
return pwd.policy.min <= occurences <= pwd.policy.max
def solve(passwords: List[Password]) -> int:
return sum(map(is_valid, passwords))
def main() -> None:
pattern = re.compile("([0-9]+)-([0-9]+) (.): (.+)")
input = [
Password(Policy(int(m.group(1)), int(m.group(2)), m.group(3)), m.group(4))
for m in (pattern.match(line) for line in sys.stdin.readlines())
if m
]
print(solve(input))
if __name__ == "__main__":
main()