41 lines
941 B
Python
41 lines
941 B
Python
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#!/usr/bin/env python
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import itertools
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import sys
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from collections import defaultdict
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from typing import Dict, Iterator, List
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def nth(iterable: Iterator[int], n: int) -> int:
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return next(itertools.islice(iterable, n, None))
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def spoken(spoken: List[int]) -> Iterator[int]:
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turn = 0
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turns: Dict[int, List[int]] = defaultdict(list)
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for last in spoken:
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turn += 1
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turns[last].append(turn)
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yield last
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while True:
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if len(last_turn := turns[last]) < 2:
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last = 0
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else:
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last = last_turn[-1] - last_turn[-2]
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turn += 1
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turns[last].append(turn)
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yield last
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def solve(nums: List[int]) -> int:
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return nth(spoken(nums), 30000000 - 1)
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def main() -> None:
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input = [line.strip() for line in sys.stdin.readlines()]
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assert len(input) == 1
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print(solve([int(i) for i in input[0].split(",")]))
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if __name__ == "__main__":
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main()
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