#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
#define endl '\n'
#define pi pair<int, int>
const long long mod = 1000000007;
const int maxn = 3004;
int n, m;
long long dp[maxn][maxn];
int main(){
ios::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> m;
n += 4, m += 4;
for(long long i = 4; i < n; i++){
for(long long j = 4; j < m; j++){
dp[i][j] += 4 * (dp[i - 1][j - 1] + 1) % mod;
dp[i][j] %= mod;
dp[i][j] += (j - 4) * (dp[i - 1][j - 2] + 1) % mod + (i - 4) * (dp[i - 2][j - 1] + 1) % mod;
dp[i][j] %= mod;
dp[i][j] += 16 * (i - 4) * (j - 4) % mod * (dp[i - 2][j - 2] + 1) % mod;
dp[i][j] %= mod;
dp[i][j] += 6 * (i - 4) * (i - 5) * (j - 4) % mod * (dp[i - 3][j - 2] + 1) % mod;
dp[i][j] %= mod;
dp[i][j] += 6 * (i - 4) * (j - 4) * (j - 5) % mod * (dp[i - 2][j - 3] + 1) % mod;
dp[i][j] %= mod;
dp[i][j] += 5 * (i - 4) * (i - 5) * (j - 4) * (j - 5) / 4 % mod * (dp[i - 3][j - 3] + 1) % mod;
dp[i][j] %= mod;
dp[i][j] += (i - 4) * (i - 5) * (i - 6) * (j - 4) / 2 % mod * (dp[i - 4][j - 2] + 1) % mod;
dp[i][j] %= mod;
dp[i][j] += (i - 4) * (j - 4) * (j - 5) * (j - 6) / 2 % mod * (dp[i - 2][j - 4] + 1) % mod;
dp[i][j] %= mod;
dp[i][j] += dp[i - 1][j] + dp[i][j - 1] - dp[i - 1][j - 1] + mod;
dp[i][j] %= mod;
//cout << (i - 2) << " " << (j - 2) << ": " << dp[i][j] << endl;
}
}
cout << dp[n - 1][m - 1] << endl;
return 0;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
376 KB |
Output is correct |
| 2 |
Correct |
2 ms |
376 KB |
Output is correct |
| 3 |
Correct |
2 ms |
504 KB |
Output is correct |
| 4 |
Correct |
3 ms |
1144 KB |
Output is correct |
| 5 |
Correct |
3 ms |
760 KB |
Output is correct |
| 6 |
Correct |
4 ms |
1404 KB |
Output is correct |
| 7 |
Correct |
4 ms |
888 KB |
Output is correct |
| 8 |
Correct |
4 ms |
1528 KB |
Output is correct |
| 9 |
Correct |
2 ms |
888 KB |
Output is correct |
| 10 |
Correct |
6 ms |
1784 KB |
Output is correct |
| 11 |
Correct |
2 ms |
376 KB |
Output is correct |
| 12 |
Correct |
10 ms |
2300 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
376 KB |
Output is correct |
| 2 |
Correct |
2 ms |
376 KB |
Output is correct |
| 3 |
Correct |
2 ms |
504 KB |
Output is correct |
| 4 |
Correct |
3 ms |
1144 KB |
Output is correct |
| 5 |
Correct |
3 ms |
760 KB |
Output is correct |
| 6 |
Correct |
4 ms |
1404 KB |
Output is correct |
| 7 |
Correct |
4 ms |
888 KB |
Output is correct |
| 8 |
Correct |
4 ms |
1528 KB |
Output is correct |
| 9 |
Correct |
2 ms |
888 KB |
Output is correct |
| 10 |
Correct |
6 ms |
1784 KB |
Output is correct |
| 11 |
Correct |
2 ms |
376 KB |
Output is correct |
| 12 |
Correct |
10 ms |
2300 KB |
Output is correct |
| 13 |
Correct |
2 ms |
376 KB |
Output is correct |
| 14 |
Correct |
13 ms |
9720 KB |
Output is correct |
| 15 |
Correct |
383 ms |
55160 KB |
Output is correct |
| 16 |
Correct |
27 ms |
4092 KB |
Output is correct |
| 17 |
Correct |
87 ms |
12924 KB |
Output is correct |
| 18 |
Correct |
109 ms |
17120 KB |
Output is correct |
| 19 |
Correct |
445 ms |
63068 KB |
Output is correct |
| 20 |
Correct |
356 ms |
50908 KB |
Output is correct |
| 21 |
Correct |
235 ms |
33784 KB |
Output is correct |
| 22 |
Correct |
234 ms |
35448 KB |
Output is correct |
| 23 |
Correct |
139 ms |
27000 KB |
Output is correct |
| 24 |
Correct |
595 ms |
70924 KB |
Output is correct |
| 25 |
Correct |
451 ms |
61304 KB |
Output is correct |
| 26 |
Correct |
514 ms |
66664 KB |
Output is correct |
| 27 |
Correct |
574 ms |
69060 KB |
Output is correct |
