Submission #44125

#	Time	Username	Problem	Language	Result	Execution time	Memory
44125		tlwpdus	Tents (JOI18_tents)	C++11	100 / 100	513 ms	71292 KiB

tents

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

int n, m;
ll dp[3010][3010], MOD = 1e9+7;

int main() {
    int i, j;

    scanf("%d%d",&n,&m);
    for (i=0;i<=m;i++) dp[0][i] = 1;
    for (i=0;i<=n;i++) dp[i][0] = 1;
    for (i=1;i<=n;i++)for (j=1;j<=m;j++) dp[i][j] = (dp[i-1][j] + dp[i-1][j-1]*4*j%MOD + dp[i-2][j-1]*j*(i-1)%MOD + dp[i-1][j-2]*(1LL*j*(j-1)/2)%MOD ) %MOD;
    printf("%lld\n",(dp[n][m]+MOD-1)%MOD);

    return 0;
}

Compilation message (stderr)

tents.cpp: In function 'int main()':
tents.cpp:13:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~

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