結果

問題 No.1127 変形パスカルの三角形
ユーザー Theta
提出日時 2022-10-20 15:44:21
言語 Python3
(3.13.1 + numpy 2.2.1 + scipy 1.14.1)
結果
AC  
実行時間 1,120 ms / 1,500 ms
コード長 2,833 bytes
コンパイル時間 163 ms
コンパイル使用メモリ 12,800 KB
実行使用メモリ 11,136 KB
最終ジャッジ日時 2024-06-30 08:26:25
合計ジャッジ時間 21,222 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge5
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other AC * 30
権限があれば一括ダウンロードができます

ソースコード

diff # 

from itertools import pairwise
from math import ceil


class Modint:

    MOD = int(1e9+7)

    def __init__(self, value: int) -> None:
        self.num = int(value) % self.MOD

    def __str__(self) -> str:
        return str(self.num)

    __repr__ = __str__

    def __add__(self, __x):
        if isinstance(__x, Modint):
            return Modint((self.num + __x.num))
        return Modint(self.num + __x)

    def __sub__(self, __x):
        if isinstance(__x, Modint):
            return Modint(self.num - __x.num)
        return Modint(self.num - __x)

    def __mul__(self, __x):
        if isinstance(__x, Modint):
            return Modint(self.num * __x.num)
        return Modint(self.num * __x)

    __radd__ = __add__
    __rmul__ = __mul__

    def __rsub__(self, __x):
        if isinstance(__x, Modint):
            return Modint(__x.num - self.num)
        return Modint(__x - self.num)

    def __pow__(self, __x):
        if isinstance(__x, Modint):
            return Modint(pow(self.num, __x.num, self.MOD))
        return Modint(pow(self.num, __x, self.MOD))

    def __rpow__(self, __x):
        if isinstance(__x, Modint):
            return Modint(pow(__x.num, self.num, self.MOD))
        return Modint(pow(__x, self.num, self.MOD))

    def __truediv__(self, __x):
        if isinstance(__x, Modint):
            return Modint(self.num * pow(__x.num, self.MOD - 2, self.MOD))
        return Modint(self.num * pow(__x, self.MOD - 2, self.MOD))

    def __rtruediv__(self, __x):
        if isinstance(__x, Modint):
            return Modint(__x.num * pow(self.num, self.MOD - 2, self.MOD))
        return Modint(__x * pow(self.num, self.MOD - 2, self.MOD))


def main():
    a, b = map(int, input().split())
    n, k = map(int, input().split())

    current_a_coeff = Modint(1)
    current_b_coeff = Modint(0)
    ans_a_coeff = 1
    ans_b_coeff = 0
    coeff_two = Modint(1)
    coeff_ab = Modint(0)
    for k_ in range(1, (n+2)//2):

        current_b_coeff = current_a_coeff
        current_a_coeff = current_a_coeff * (n-k_)/k_
        if k_ == (k-1):
            ans_a_coeff = current_a_coeff
            ans_b_coeff = current_b_coeff
        elif k_ == (n+1-k):
            ans_a_coeff = current_b_coeff
            ans_b_coeff = current_a_coeff
        # current.append([current[-1][0]*(n-k_)//k_, current[-1][0]])
        coeff_two += current_a_coeff ** 2
        coeff_two += current_b_coeff ** 2
        coeff_ab += 4 * current_a_coeff * current_b_coeff
    if n % 2 == 0:
        coeff_two -= current_a_coeff ** 2
        coeff_ab -= 2 * current_a_coeff * current_b_coeff

    print(Modint(a) * ans_a_coeff +
          Modint(b) * ans_b_coeff)
    print(coeff_two * Modint(a)**2 + coeff_two * Modint(b)
          ** 2 + coeff_ab * Modint(a) * Modint(b))


if __name__ == "__main__":
    main()
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