Submission #1006744

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Source Code Expand

#include <iostream>

using namespace std;

typedef long long ll;

ll n, m;

ll dp[310][310][310];

const ll MOD = 1e9 + 7;

int main(){
	cin>>n>>m;
	dp[0][1][1] = 1LL;
	for(int i = 0; i < m; i++) {
		for(int j = 0; j <= n; j++) {
			for(int k = 0; k <= n; k++) {
				(dp[i+1][j+1][k] += dp[i][j][k] * (n - j)) %= MOD;
				(dp[i+1][j][k] += dp[i][j][k] * (j - k)) %= MOD;
				(dp[i+1][j][j] += dp[i][j][k] * k) %= MOD;
			}
		}
	}
	cout << dp[m][n][n] << endl;
}

Submission Info

Judge Result