Submission #2005754

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Source Code Expand

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<algorithm>
using namespace std;

const int N=305;
const int mod=1000000007;

int n,m;
int dp[2][N][N];

int main(){
	int i,j,k,now,pre,w;
	scanf("%d%d",&n,&m);
	if (m<n){
		printf("0\n");
		return 0;
	}
	now=0; pre=1;
	dp[0][1][1]=1;
	for (i=1;i<=m;i++){
		now^=1; pre^=1;
		for (j=1;j<=i;j++)
			for (k=1;k<=i&&k<=j;k++){
				if (!dp[pre][j][k]) continue;
				w=dp[pre][j][k];
				(dp[now][j+1][k]+=1ll*w*(n-j)%mod)%=mod;
				(dp[now][j][k]+=1ll*w*(j-k)%mod)%=mod;
				(dp[now][j][j]+=1ll*w*k%mod)%=mod;
			}
		memset(dp[pre],0,sizeof(dp[pre]));
	}
	printf("%d\n",dp[now][n][n]);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:17:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
                     ^

Judge Result