46 lines
1.1 KiB
Python
46 lines
1.1 KiB
Python
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#!/usr/bin/env python
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import math
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import sys
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from typing import Dict, List
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def run_contest(timings: List[int]) -> int:
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# https://rosettacode.org/wiki/Chinese_remainder_theorem#Python_3.6
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def mul_inv(a: int, b: int) -> int:
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b0 = b
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x0, x1 = 0, 1
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if b == 1:
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return 1
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while a > 1:
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q = a // b
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a, b = b, a % b
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x0, x1 = x1 - q * x0, x0
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if x1 < 0:
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x1 += b0
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return x1
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def chinese_remainder(residue_mapping: Dict[int, int]) -> int:
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res = 0
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prod = math.prod(residue_mapping)
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for n_i, a_i in residue_mapping.items():
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p = prod // n_i
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res += a_i * mul_inv(p, n_i) * p
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return res % prod
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residues = {t: -i for (i, t) in enumerate(timings) if t > 0}
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return chinese_remainder(residues)
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def solve(raw: List[str]) -> int:
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return run_contest([int(i) if i != "x" else -1 for i in raw[1].split(",")])
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def main() -> None:
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input = [line.strip() for line in sys.stdin.readlines()]
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print(solve(input))
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if __name__ == "__main__":
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main()
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