advent-of-code/2020/d16/ex1/ex1.py

60 lines
1.4 KiB
Python
Executable file

#!/usr/bin/env python
import sys
from typing import Dict, List, Set, Tuple
Ranges = Dict[str, Set[int]]
Ticket = List[int]
def parse(raw: List[str]) -> Tuple[Ranges, List[Ticket]]:
def extract_field_info(line: str) -> Tuple[str, Set[int]]:
field, rest = line.split(":")
ranges: Set[int] = set()
for r in rest.strip().split(" or "):
lhs, rhs = r.split("-")
ranges |= set(range(int(lhs), int(rhs) + 1))
return field, ranges
def parse_tickets(line: str) -> Ticket:
return [int(i) for i in line.split(",")]
ranges: Ranges = {}
tickets: List[Ticket] = []
should_parse_tickets = False
for line in raw:
if line == "":
should_parse_tickets = True
continue
if "ticket" in line:
continue
if should_parse_tickets:
tickets.append(parse_tickets(line))
else:
field, field_ranges = extract_field_info(line)
ranges[field] = field_ranges
return ranges, tickets
def solve(raw: List[str]) -> int:
ranges, tickets = parse(raw)
sum = 0
for ticket in tickets[1:]:
for val in ticket:
if any(val in r for r in ranges.values()):
continue
sum += val
return sum
def main() -> None:
input = [line.strip() for line in sys.stdin.readlines()]
print(solve(input))
if __name__ == "__main__":
main()