//In His Name
#include <bits/stdc++.h>
//#pragma GCC optimization("O3")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("avx2")
using namespace std;
#define ll long long
#define int ll
typedef pair<int, int> pii;
#define F first
#define S second
#define pb push_back
#define bug(x) cout << "Ah shit , here we go again : " << x <<endl
#define all(x) x.begin() , x.end()
const int maxn = 3e3 + 10, MOD = 1e9 + 7;
const ll INF = 1e18;
int n , m , dp[maxn][maxn];
int32_t main(){
ios_base::sync_with_stdio(false);
cin >> n >> m;
for(int i = 1 ; i <= n ; i++) dp[i][0] = 1 , dp[i][1] = (4 * i + (i*(i-1)/2) + 1) % MOD;
for(int i = 1 ; i <= m ; i++) dp[0][i] = 1 , dp[1][i] = (4 * i + (i*(i-1)/2) + 1) % MOD;
dp[0][0] = 1;
for(int i = 2 ; i <= n; i++){
for(int j = 2 ; j <= m ; j++){
dp[i][j] = dp[i-1][j] % MOD;
dp[i][j] += (4 * j * dp[i-1][j-1]) % MOD;
dp[i][j] += (j * (i-1) * dp[i-2][j-1]) % MOD;
dp[i][j] += (j * (j-1) / 2 * dp[i-1][j-2]) % MOD;
}
}
cout << (dp[n][m] + MOD - 1) % MOD;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
1 ms |
604 KB |
Output is correct |
| 3 |
Correct |
1 ms |
2396 KB |
Output is correct |
| 4 |
Correct |
1 ms |
6492 KB |
Output is correct |
| 5 |
Correct |
1 ms |
2396 KB |
Output is correct |
| 6 |
Correct |
1 ms |
6492 KB |
Output is correct |
| 7 |
Correct |
1 ms |
2516 KB |
Output is correct |
| 8 |
Correct |
1 ms |
6492 KB |
Output is correct |
| 9 |
Correct |
1 ms |
4444 KB |
Output is correct |
| 10 |
Correct |
1 ms |
8540 KB |
Output is correct |
| 11 |
Correct |
1 ms |
2392 KB |
Output is correct |
| 12 |
Correct |
2 ms |
8696 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
1 ms |
604 KB |
Output is correct |
| 3 |
Correct |
1 ms |
2396 KB |
Output is correct |
| 4 |
Correct |
1 ms |
6492 KB |
Output is correct |
| 5 |
Correct |
1 ms |
2396 KB |
Output is correct |
| 6 |
Correct |
1 ms |
6492 KB |
Output is correct |
| 7 |
Correct |
1 ms |
2516 KB |
Output is correct |
| 8 |
Correct |
1 ms |
6492 KB |
Output is correct |
| 9 |
Correct |
1 ms |
4444 KB |
Output is correct |
| 10 |
Correct |
1 ms |
8540 KB |
Output is correct |
| 11 |
Correct |
1 ms |
2392 KB |
Output is correct |
| 12 |
Correct |
2 ms |
8696 KB |
Output is correct |
| 13 |
Correct |
1 ms |
348 KB |
Output is correct |
| 14 |
Correct |
10 ms |
55812 KB |
Output is correct |
| 15 |
Correct |
41 ms |
66136 KB |
Output is correct |
| 16 |
Correct |
3 ms |
6748 KB |
Output is correct |
| 17 |
Correct |
10 ms |
16988 KB |
Output is correct |
| 18 |
Correct |
12 ms |
29272 KB |
Output is correct |
| 19 |
Correct |
44 ms |
70256 KB |
Output is correct |
| 20 |
Correct |
35 ms |
60116 KB |
Output is correct |
| 21 |
Correct |
23 ms |
39516 KB |
Output is correct |
| 22 |
Correct |
23 ms |
51804 KB |
Output is correct |
| 23 |
Correct |
17 ms |
70492 KB |
Output is correct |
| 24 |
Correct |
56 ms |
71032 KB |
Output is correct |
| 25 |
Correct |
42 ms |
62044 KB |
Output is correct |
| 26 |
Correct |
57 ms |
68344 KB |
Output is correct |
| 27 |
Correct |
54 ms |
70392 KB |
Output is correct |
