advent-of-code/2024/d03/ex2/ex2.py

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2024-12-03 11:13:19 +01:00
#!/usr/bin/env python
import dataclasses
import re
import sys
@dataclasses.dataclass
class MulInstruction:
lhs: int
rhs: int
def calc(self) -> int:
return self.lhs * self.rhs
def solve(input: str) -> int:
def parse(input: str) -> list[MulInstruction]:
res: list[MulInstruction] = []
MUL_REGEX = re.compile(r"do\(\)|don't\(\)|mul\((\d+),(\d+)\)")
do = True
for match in MUL_REGEX.finditer(input):
if match.group(0) in ("do()", "don't()"):
do = match.group(0) == "do()"
continue
if not do:
continue
res.append(MulInstruction(int(match.group(1)), int(match.group(2))))
return res
return sum(inst.calc() for inst in parse(input))
def main() -> None:
input = sys.stdin.read()
print(solve(input))
if __name__ == "__main__":
main()