42 lines
991 B
Python
Executable file
42 lines
991 B
Python
Executable file
#!/usr/bin/env python
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import sys
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from typing import NamedTuple
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class ProgramYell(NamedTuple):
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weight: int
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children: set[str]
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Tower = dict[str, ProgramYell]
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def solve(input: str) -> str:
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def parse_line(line: str) -> tuple[str, ProgramYell]:
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name, rest = line.split(" ", 1)
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weight, rest = rest.split(")")
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children = set(rest.removeprefix(" -> ").split(", ")) if rest else set()
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return name, ProgramYell(int(weight[1:]), children)
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def parse(input: str) -> Tower:
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return {name: yell for name, yell in map(parse_line, input.splitlines())}
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def find_base(tower: Tower) -> str:
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candidates = set(tower.keys())
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for yell in tower.values():
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candidates -= yell.children
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assert len(candidates) == 1
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return candidates.pop()
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tower = parse(input)
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return find_base(tower)
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def main() -> None:
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input = sys.stdin.read()
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print(solve(input))
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if __name__ == "__main__":
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main()
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