分情况:
第一盆k种选择,之后全部k-1种选择
每次相乘结果对1e9+7取模
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
#define endl '\n'
const int N = 1e9 + 7;int main() {ios::sync_with_stdio(false);cin.tie(0); cout.tie(0);int t, n, k;cin >> t;while (t--) {long long sum = 1;cin >> n >> k;for (int i = 1; i <= n; i++) {if (i == 1) sum *= k;else {sum *= k - 1;sum %= N;}}cout << sum << endl;}return 0;
}