Submission #1033997

#	Time	Username	Problem	Language	Result	Execution time	Memory
1033997		vjudge1	Tents (JOI18_tents)	C++14	100 / 100	121 ms	70908 KiB

tents

#include<bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
    int n,m;
    cin >> n >> m;
    const int mod=1e9+7;
    int DP[n+1][m+1];
    for(int j=0;j<=m;j++){
        DP[0][j]=1;
    }
    for(int i=1;i<=n;i++){
        for(int j=0;j<=m;j++){
            DP[i][j]=0;
            if(i>1&&j>0){
                DP[i][j]+=(DP[i-2][j-1]*((j*(i-1))%mod));
                DP[i][j]%=mod;
            }
            if(j>1){
                DP[i][j]=(DP[i][j]+((DP[i-1][j-2]*((j*(j-1)/2)%mod))%mod));
                DP[i][j]%=mod;
            }
            if(j>0){
                DP[i][j]=(DP[i][j]+((4*DP[i-1][j-1]*j)%mod));
                DP[i][j]%=mod;
            }
            DP[i][j]+=DP[i-1][j];
            DP[i][j]%=mod;
        }
    }
    cout << (DP[n][m]+mod-1)%mod;
}

• Subtask 1: 48 / 48
• Subtask 2: 52 / 52