Submission #1109771

#	Time	Username	Problem	Language	Result	Execution time	Memory
1109771		Warinchai	Tents (JOI18_tents)	C++14	100 / 100	88 ms	70984 KiB

tents

#include<bits/stdc++.h>
#define int long long
using namespace std;
int dp[3005][3005];
int md=1e9+7;
int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int h,w;cin>>h>>w;
    for(int i=0;i<=h;i++)dp[i][0]=1;
    for(int i=0;i<=w;i++)dp[0][i]=1;
    for(int i=1;i<=h;i++){
        for(int j=1;j<=w;j++){
            dp[i][j]=(dp[i][j]+dp[i-1][j-1]*j*4+dp[i-1][j])%md;
            if(j>1)dp[i][j]=(dp[i][j]+dp[i-1][j-2]*(j)*(j-1)/2)%md;
            if(i>1)dp[i][j]=(dp[i][j]+(i-1)*j*dp[i-2][j-1])%md;
        }
    }
    cout<<(dp[h][w]-1+md)%md<<"\n";
}
//ill finish later

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