Submission #1010362

#	Time	Username	Problem	Language	Result	Execution time	Memory
1010362		snpmrnhlol	Tents (JOI18_tents)	C++17	100 / 100	98 ms	35456 KiB

tents

#include<bits/stdc++.h>
using namespace std;
const int N = 3e3;
const int mod = 1e9 + 7;
int dp[N + 1][N + 1];
int main(){
    int n,m;
    cin>>n>>m;
    dp[0][0] = 1;
    for(int i = 0;i <= n;i++){
        for(int j = 0;j <= m;j++){
            if(i == 0 || j == 0){
                dp[i][j] = 1;
                continue;
            }
            dp[i][j] = dp[i - 1][j];
            dp[i][j] = (dp[i][j] + 1ll*4*j*dp[i - 1][j - 1]%mod)%mod;
            if(i >= 2)dp[i][j] = (dp[i][j] + 1ll*j*(i - 1)*dp[i - 2][j - 1]%mod)%mod;
            if(j >= 2)dp[i][j] = (dp[i][j] + 1ll*j*(j - 1)/2*dp[i - 1][j - 2]%mod)%mod;
            //cout<<dp[i][j]<<' ';
        }
        //cout<<'\n';
    }
    cout<<(dp[n][m] - 1 + mod)%mod<<' ';
    return 0;
}

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