提出 #17628948

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ソースコード 拡げる

import sys
import numpy as np
import numba
from numba import njit, b1, i4, i8, f8

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

MOD = 998_244_353

def from_read(dtype=np.int64):
    return np.fromstring(read().decode(), dtype=dtype, sep=' ')


def from_readline(dtype=np.int64):
    return np.fromstring(readline().decode(), dtype=dtype, sep=' ')

@njit
def mpow(a, n):
    p = 1
    while n:
        if n & 1:
            p = p * a % MOD
        a = a * a % MOD
        n >>= 1
    return p


@njit
def fact_table(N):
    N += 1
    fact = np.empty(N, np.int64)
    fact[0] = 1
    for n in range(1, N):
        fact[n] = n * fact[n - 1] % MOD
    fact_inv = np.empty(N, np.int64)
    fact_inv[N - 1] = mpow(fact[N - 1], MOD - 2)
    for n in range(N - 1, 0, -1):
        fact_inv[n - 1] = fact_inv[n] * n % MOD
    inv = np.empty(N, np.int64)
    inv[0] = 0
    inv[1:] = fact[:-1] * fact_inv[1:] % MOD
    return fact, fact_inv, inv

@njit((i8[:], ), cache=True)
def main(A):

    N = len(A)
    A %= MOD
    fact, fact_inv, inv = fact_table(N + 10)
    B = (A - 1) % MOD
    S = B.sum() % MOD
    coef = fact[N - 2] % MOD
    for a in A:
        coef *= a
        coef %= MOD
    # comb(S, N-2)
    x = 1
    for i in range(1, N - 1):
        x = x * (S - i + 1) % MOD
        x = x * inv[i] % MOD
    return x * coef % MOD

A = from_read()[1:]

print(main(A))

提出情報

ジャッジ結果