23.7.27 牛客暑期多校4部分题解

1010 - Kong Ming Qi

1005 - Data Generation

题意、思路待补

code

#include <bits/stdc++.h>
using namespace std;
const long long MOD = 998244353;
int t;
long long n, m;
long long sub(long long a, long long b) {return a - b < 0 ? a - b + MOD : a - b;}
long long mul(long long a, long long b) {return a * b % MOD;}
long long pw(long long a, long long b) {long long res = 1;while (b) {if (b & 1) res = mul(res, a);a = mul(a, a);b >>= 1;}return res;
}
int main() {scanf("%d", &t);while (t --) {scanf("%lld%lld", &n, &m); n %= MOD;printf("%lld\n", mul(sub(n, 1), sub(1, pw(mul(sub(n, 2), pw(n, MOD - 2)), m))));}return 0;
}