Submission #45875

#	Time	Username	Problem	Language	Result	Execution time	Memory
45875		3zp	Tents (JOI18_tents)	C++14	100 / 100	207 ms	71268 KiB

tents

#include<bits/stdc++.h>
using namespace std;
long long dp[3009][3009];
long long mod = 1e9+7;
main(){
    long long H,W;
    cin >> H>> W;
    for (long long i = 1; i<= H; i++){
        dp[i][1]= i*(i-1)/2+4*i+1;
        dp[i][0]= 1;
    }
    for (long long j=1; j<=W; j++){
        dp[1][j] =j*(j-1)/2+4*j+1;
        dp[0][j] = 1;
    }
    for(long long i =2; i<= H; i++){
        for (long long j =  2; j<= W; j++){
            dp[i][j]= (dp[i-1][j]+(4*j*dp[i-1][j-1])+j*(i-1)*dp[i-2][j-1]+j*(j-1)/2*dp[i-1][j-2])%mod;
        }
    }
    cout<<(dp[H][W] + mod -1 )%mod<<endl;
}

Compilation message (stderr)

tents.cpp:5:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^

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