제출 #1340574

#제출 시각아이디문제언어결과실행 시간메모리
1340574po_rag526Zapina (COCI20_zapina)C++17
110 / 110
109 ms2300 KiB
#include<bits/stdc++.h>
using namespace std;
#define FAST_IO ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define int long long
#define MAXN 355
const int MOD=1e9+7;
int n;
int dp[MAXN][MAXN];
int C[MAXN][MAXN];
void init()
{
	for(int i=0;i<=n;i++) C[i][0]=1;
	for(int i=1;i<=n;i++) for(int j=1;j<=i;j++) C[i][j]=(C[i-1][j]+C[i-1][j-1])%MOD;
}
int qp(int a,int b)
{
	int res=1;
	while(b>0)
	{
		if(b&1) res=res*a%MOD;
		a=a*a%MOD;
		b>>=1;
	}
	return res;
}
signed main()
{
	FAST_IO;
	cin>>n;
	init();
	dp[0][0]=1;
	for(int i=1;i<=n;i++)
	{
		for(int j=0;j<=n;j++)
		{
			for(int k=0;k<=j;k++)
			{
				if(k==i) continue;
				dp[i][j]=(dp[i][j]+dp[i-1][j-k]*C[j][k]%MOD)%MOD;
			}
		}
	}
	int ans=(qp(n,n)-dp[n][n]+MOD)%MOD;
	cout<<ans<<'\n';
	return 0;
}
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...