Submission #49323

#	Time	Username	Problem	Language	Result	Execution time	Memory
49323		okaybody10	Tents (JOI18_tents)	C++11	100 / 100	439 ms	59340 KiB

tents

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MOD = 1e9+7;
ll dp[3005][3005];
ll d(int h,int w)
{
    if(h<0 || w<0) return 0;
    if(h==0 || w==0) return 1;
    if(dp[h][w]) return dp[h][w];
    ll ret=0;
    ret+=d(h-1,w); ret%=MOD;
    ret+=4*w*d(h-1,w-1); ret%=MOD;
    ret+=w*(w-1)/2*d(h-1,w-2); ret%=MOD;
    ret+=(h-1)*w*d(h-2,w-1); ret%=MOD;
    return dp[h][w]=ret%MOD;
}
int main(){
    int h,w; scanf("%d %d",&w,&h);
    d(h,w);
    printf("%lld",(dp[h][w]+MOD-1)%MOD);
    return 0;
}

Compilation message (stderr)

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

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