Submission #5024961

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Source Code Expand

#include<bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define fin(x) freopen(x,"r",stdin)
#define fout(x) freopen(x,"w",stdout)
#define mem(a,b) memset(a,b,sizeof(a))
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
const ll INF=0x3f3f3f3f3f3f3f3f;
const ll inf=0xc0c0c0c0c0c0c0c0;
const double pi=acos(-1);
const int MAX=305;
const ll mod=1e9+7;
ll dp[2][MAX][MAX];//len,maxid,connectone
ll N,M;
void add(ll &a,ll b){a=(a+b)%mod;}
ll fact(ll x)
{
	ll res=1;
	while(x)
	{
		res=res*x%mod;
		x--;
	}
	return res;
}
int main()
{
	scanf("%lld%lld",&N,&M);
	dp[0][1][1]=1;
	for(int i=0;i<M;i++)
	{
		int last=i&1;
		int now=last^1;
		mem(dp[now],0);
		for(int j=0;j<=N;j++)
			for(int k=0;k<=j;k++)
				if(dp[last][j][k])
				{
					add(dp[now][j][j],dp[last][j][k]*k%mod);//connect 1
					if(j<N)
						add(dp[now][j+1][k],dp[last][j][k]);//new
					add(dp[now][j][k],dp[last][j][k]*(j-k)%mod);//connect not 1
				}
	}
	printf("%lld\n",dp[M&1][N][N]*fact(N-1)%mod);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:32:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld%lld",&N,&M);
                         ^

Judge Result