Jubilee

#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for(int i = a; i < (b); i++)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

const int N = 1e6 + 5;
const int MOD = 1e9 + 7;

void add(int &a, int b) {
    a += b;
    if (a >= MOD) {
        a -= MOD;
    }
}

void sub(int &a, int b) {
    a -= b;
    if (a < 0) {
        a += MOD;
    }
}

int mul(int a, int b) {
    return 1LL * a * b % MOD;
}

int n, m;
int f[N];

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    cin >> n >> m;
    if (m == 1) {
        cout << 0 << '\n';
        return 0;
    }
    f[1] = mul(m, m - 1);
    for (int i = 2; i <= n; i++) {
        int mm = mul(m - 1, m - 1);
        sub(mm, m - 2);
        f[i] = mul(f[i - 1], mm);
    }
    cout << f[n] << '\n';
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED