advent-of-code/2021/d12/ex1/ex1.py
Bruno BELANYI f9fc9fbd6b treewide: fix 'ruff check' errors
This is mostly about unused imports.

A couple errors remain, but are fine in my book (using `l` as a variable
name, assigning a lambda to a variable).
2024-11-23 19:24:55 +00:00

46 lines
882 B
Python
Executable file

#!/usr/bin/env python
import sys
from collections import defaultdict
from typing import Dict, List, Set
Map = Dict[str, Set[str]]
def solve(input: List[str]) -> int:
def parse() -> Map:
res: Map = defaultdict(set)
for start, to in map(lambda s: s.split("-"), input):
res[start].add(to)
res[to].add(start)
return res
caves = parse()
def dfs(start: str, seen: Set[str] = set()) -> int:
if start == "end":
return 1
seen = seen | {start}
res = 0
for dest in caves[start]:
if dest in seen and dest.islower():
continue
res += dfs(dest, seen)
return res
return dfs("start")
def main() -> None:
input = [line.strip() for line in sys.stdin.readlines()]
print(solve(input))
if __name__ == "__main__":
main()