#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
#define ll long long
#define lol long long
#define pb push_back
//#define mp make_pair
#define fr first
#define sc second
#define MAX ((lol)(1e9+100))
#define MX ((lol)(4e9+100))
#define ARRS ((lol)(5e5+100))
#define MOD ((lol)(1e9+7))
#define EP ((double)(1e-9))
#define EPS ((double)(1e-8))
#define pb push_back
#define PI ((double)3.141592653)
#define LG 21
ll dp[4000][4000];
ll go(ll n,ll m){
if(n<0||m<0)return 0;
if(n==0||m==0)return 1;
if(dp[n][m]>=0)return dp[n][m];
// cout<<m*(m-1)/2<<endl;
// 10 1*1
dp[n][m]=go(n-1,m)+m*(m-1)/2*go(n-1,m-2)+m*(n-1)*go(n-2,m-1)+m*4*go(n-1,m-1);
// cout<<n<<" "<<m<<" "<<dp[n][m]<<endl;
dp[n][m]%=MOD;
return dp[n][m];
}
int main(){
#ifdef KHOKHO
freopen("in.in","r",stdin);
freopen("out.out","w",stdout);
#endif // KHOKHO
ios::sync_with_stdio(0);
ll n,m;
cin>>n>>m;
for(int i=0; i<=n; i++){
for(int j=0; j<=m; j++){
dp[i][j]=-1;
}
}
cout<<go(n,m)-1;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
488 KB |
Output is correct |
3 |
Correct |
2 ms |
608 KB |
Output is correct |
4 |
Correct |
2 ms |
1176 KB |
Output is correct |
5 |
Correct |
2 ms |
1176 KB |
Output is correct |
6 |
Correct |
3 ms |
1440 KB |
Output is correct |
7 |
Correct |
2 ms |
1440 KB |
Output is correct |
8 |
Correct |
3 ms |
1452 KB |
Output is correct |
9 |
Correct |
2 ms |
1452 KB |
Output is correct |
10 |
Correct |
3 ms |
2036 KB |
Output is correct |
11 |
Correct |
2 ms |
2036 KB |
Output is correct |
12 |
Correct |
4 ms |
2540 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
488 KB |
Output is correct |
3 |
Correct |
2 ms |
608 KB |
Output is correct |
4 |
Correct |
2 ms |
1176 KB |
Output is correct |
5 |
Correct |
2 ms |
1176 KB |
Output is correct |
6 |
Correct |
3 ms |
1440 KB |
Output is correct |
7 |
Correct |
2 ms |
1440 KB |
Output is correct |
8 |
Correct |
3 ms |
1452 KB |
Output is correct |
9 |
Correct |
2 ms |
1452 KB |
Output is correct |
10 |
Correct |
3 ms |
2036 KB |
Output is correct |
11 |
Correct |
2 ms |
2036 KB |
Output is correct |
12 |
Correct |
4 ms |
2540 KB |
Output is correct |
13 |
Correct |
2 ms |
2540 KB |
Output is correct |
14 |
Correct |
8 ms |
10108 KB |
Output is correct |
15 |
Correct |
131 ms |
55728 KB |
Output is correct |
16 |
Correct |
5 ms |
55728 KB |
Output is correct |
17 |
Correct |
19 ms |
55728 KB |
Output is correct |
18 |
Correct |
33 ms |
55728 KB |
Output is correct |
19 |
Correct |
151 ms |
63612 KB |
Output is correct |
20 |
Correct |
117 ms |
63612 KB |
Output is correct |
21 |
Correct |
70 ms |
63612 KB |
Output is correct |
22 |
Correct |
76 ms |
63612 KB |
Output is correct |
23 |
Correct |
54 ms |
63612 KB |
Output is correct |
24 |
Correct |
200 ms |
82812 KB |
Output is correct |
25 |
Correct |
145 ms |
82812 KB |
Output is correct |
26 |
Correct |
196 ms |
82812 KB |
Output is correct |
27 |
Correct |
292 ms |
82812 KB |
Output is correct |