#include <bits/stdc++.h>
using namespace std ;
const int mod = 1e9 + 7 ;
int Add(int x , int y)
{
int z = x + y ;
if(z >= mod)
z -= mod ;
return z ;
}
int Sub(int x , int y)
{
int z = x - y ;
if(z < 0)
z += mod ;
return z ;
}
int Mul(int x , int y)
{
return (1ll * x * y) % mod ;
}
const int MAX = 3000 + 10 ;
int arr[MAX] ;
int n , m ;
int dp[MAX][MAX] ;
int main()
{
ios_base::sync_with_stdio(0) ;
cin.tie(0) ;
cin>>n>>m ;
for(int i = 0 ; i <= max(n , m) ; ++i)
dp[0][i] = dp[i][0] = 1 ;
for(int i = 1 ; i <= n ; ++i)
{
for(int j = 1 ; j <= m ; ++j)
{
dp[i][j] = Add(dp[i-1][j] , Mul(dp[i-1][j-1] , 4*j)) ;
if(j >= 2)
dp[i][j] = Add(dp[i][j] , Mul(dp[i-1][j-2] , j * (j-1) / 2)) ;
if(i >= 2)
dp[i][j] = Add(dp[i][j] , Mul(dp[i-2][j-1] , (i-1) * j)) ;
}
}
return cout<<Sub(dp[n][m] , 1)<<"\n" , 0 ;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
1 ms |
980 KB |
Output is correct |
3 |
Correct |
1 ms |
452 KB |
Output is correct |
4 |
Correct |
1 ms |
1108 KB |
Output is correct |
5 |
Correct |
1 ms |
1360 KB |
Output is correct |
6 |
Correct |
2 ms |
1236 KB |
Output is correct |
7 |
Correct |
1 ms |
1236 KB |
Output is correct |
8 |
Correct |
1 ms |
1352 KB |
Output is correct |
9 |
Correct |
1 ms |
724 KB |
Output is correct |
10 |
Correct |
1 ms |
1612 KB |
Output is correct |
11 |
Correct |
1 ms |
1492 KB |
Output is correct |
12 |
Correct |
2 ms |
1876 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
1 ms |
980 KB |
Output is correct |
3 |
Correct |
1 ms |
452 KB |
Output is correct |
4 |
Correct |
1 ms |
1108 KB |
Output is correct |
5 |
Correct |
1 ms |
1360 KB |
Output is correct |
6 |
Correct |
2 ms |
1236 KB |
Output is correct |
7 |
Correct |
1 ms |
1236 KB |
Output is correct |
8 |
Correct |
1 ms |
1352 KB |
Output is correct |
9 |
Correct |
1 ms |
724 KB |
Output is correct |
10 |
Correct |
1 ms |
1612 KB |
Output is correct |
11 |
Correct |
1 ms |
1492 KB |
Output is correct |
12 |
Correct |
2 ms |
1876 KB |
Output is correct |
13 |
Correct |
3 ms |
7636 KB |
Output is correct |
14 |
Correct |
4 ms |
9544 KB |
Output is correct |
15 |
Correct |
57 ms |
32792 KB |
Output is correct |
16 |
Correct |
7 ms |
7892 KB |
Output is correct |
17 |
Correct |
13 ms |
12408 KB |
Output is correct |
18 |
Correct |
16 ms |
11716 KB |
Output is correct |
19 |
Correct |
78 ms |
34508 KB |
Output is correct |
20 |
Correct |
47 ms |
29120 KB |
Output is correct |
21 |
Correct |
32 ms |
21504 KB |
Output is correct |
22 |
Correct |
31 ms |
22160 KB |
Output is correct |
23 |
Correct |
20 ms |
19668 KB |
Output is correct |
24 |
Correct |
79 ms |
35576 KB |
Output is correct |
25 |
Correct |
64 ms |
30772 KB |
Output is correct |
26 |
Correct |
78 ms |
33484 KB |
Output is correct |
27 |
Correct |
77 ms |
34840 KB |
Output is correct |