Submission #164316

#	Time	Username	Problem	Language	Result	Execution time	Memory
164316		str0ct	Tents (JOI18_tents)	C++14	100 / 100	387 ms	59384 KiB

tents

#include<bits/stdc++.h>
using namespace std;
using ll=long long;
const ll mod=1e9+7;
ll dp[3030][3030];
ll f(ll col,ll row){
    //printf("%d%d\n",col,row);
    if(col<0||row<0)return 0;
    if(col==0||row==0)return 1;
    if(dp[col][row])return dp[col][row];
    dp[col][row]+=(f(col-1,row)+4*row*f(col-1,row-1))%mod;
    dp[col][row]%=mod;
    dp[col][row]+=(row*(row-1)/2*f(col-1,row-2)+row*(col-1)*f(col-2,row-1))%mod;
    dp[col][row]%=mod;
    return dp[col][row];
}
int main(){
    ll H,W;
    scanf("%lld%lld",&H,&W);
    printf("%lld",f(H,W)-1);
}

Compilation message (stderr)

tents.cpp: In function 'int main()':
tents.cpp:19:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld%lld",&H,&W);
     ~~~~~^~~~~~~~~~~~~~~~~~

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