#include <iostream>
#define MOD 1000000007
using namespace std;
int dp_ind[3001][3001];
int dp_ttl[3001][3001];
int main () {
int n, m;
cin >> n >> m;
for (int i=1; i<=n; i++) {
for (int j=1; j<=m; j++) {
dp_ind[i][j] = (4ll*(dp_ttl[i-1][j-1]+1))%MOD;
dp_ind[i][j] += (1ll*(dp_ttl[max(0, i-2)][j-1]+(i>1?1:0))*(i-1)+(dp_ttl[i-1][max(0, j-2)]+(j>1?1:0))*(j-1))%MOD;
dp_ttl[i][j] = (1ll*dp_ttl[i-1][j]+dp_ttl[i][j-1]-dp_ttl[i-1][j-1]+dp_ind[i][j]+MOD)%MOD;
}
}
// cout << dp_ind[n][m] << endl;
cout << dp_ttl[n][m] << endl;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
256 KB |
Output is correct |
2 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
256 KB |
Output is correct |
2 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |