#include <iostream>
typedef long long ll;
using namespace std;
const int mod = 1e9 + 7, maxn = 3005;
int add(const int& a, const int& b) { return (a + b) % mod; }
int mul(const int& a, const int& b) { return (a * 1ll * b) % (ll)mod; }
void upd(int& a, const int& b) { a = (a + b) % mod; }
int dp[maxn][maxn], p[maxn][maxn];
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
p[0][0] = 1;
for (int i = 1; i < maxn; i++)
{
p[i][0] = p[i][i] = 1;
for (int j = 1; j < i; j++) p[i][j] = add(p[i - 1][j - 1], p[i - 1][j]);
}
dp[0][0] = 1;
int h, w;
cin >> h >> w;
for (int i = 0; i < h; i++) for (int j = 0; j < w; j++)
{
upd(dp[i + 1][j + 1], mul(dp[i][j], mul(4, j + 1)));
if (i + 2 <= h) upd(dp[i + 2][j + 1], mul(dp[i][j], mul(i + 1, j + 1)));
if (j + 2 <= w) upd(dp[i + 1][j + 2], mul(dp[i][j], (j + 1) * (j + 2)/ 2));
}
int ans = 0;
for (int i = 1; i <= h; i++) for (int j = 1; j <= w; j++)
{
int a = mul(dp[i][j], mul(p[h][i], p[w][j]));
upd(ans, a);
}
cout << ans << "\n";
return 0;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
19 ms |
27972 KB |
Output is correct |
| 2 |
Correct |
24 ms |
27960 KB |
Output is correct |
| 3 |
Correct |
27 ms |
28184 KB |
Output is correct |
| 4 |
Correct |
24 ms |
28756 KB |
Output is correct |
| 5 |
Correct |
26 ms |
28236 KB |
Output is correct |
| 6 |
Correct |
20 ms |
28952 KB |
Output is correct |
| 7 |
Correct |
21 ms |
28364 KB |
Output is correct |
| 8 |
Correct |
21 ms |
29008 KB |
Output is correct |
| 9 |
Correct |
19 ms |
28416 KB |
Output is correct |
| 10 |
Correct |
21 ms |
29252 KB |
Output is correct |
| 11 |
Correct |
20 ms |
27936 KB |
Output is correct |
| 12 |
Correct |
27 ms |
29472 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
19 ms |
27972 KB |
Output is correct |
| 2 |
Correct |
24 ms |
27960 KB |
Output is correct |
| 3 |
Correct |
27 ms |
28184 KB |
Output is correct |
| 4 |
Correct |
24 ms |
28756 KB |
Output is correct |
| 5 |
Correct |
26 ms |
28236 KB |
Output is correct |
| 6 |
Correct |
20 ms |
28952 KB |
Output is correct |
| 7 |
Correct |
21 ms |
28364 KB |
Output is correct |
| 8 |
Correct |
21 ms |
29008 KB |
Output is correct |
| 9 |
Correct |
19 ms |
28416 KB |
Output is correct |
| 10 |
Correct |
21 ms |
29252 KB |
Output is correct |
| 11 |
Correct |
20 ms |
27936 KB |
Output is correct |
| 12 |
Correct |
27 ms |
29472 KB |
Output is correct |
| 13 |
Correct |
20 ms |
27980 KB |
Output is correct |
| 14 |
Correct |
24 ms |
37208 KB |
Output is correct |
| 15 |
Correct |
159 ms |
60484 KB |
Output is correct |
| 16 |
Correct |
28 ms |
30404 KB |
Output is correct |
| 17 |
Correct |
49 ms |
35568 KB |
Output is correct |
| 18 |
Correct |
68 ms |
38540 KB |
Output is correct |
| 19 |
Correct |
195 ms |
62192 KB |
Output is correct |
| 20 |
Correct |
148 ms |
56660 KB |
Output is correct |
| 21 |
Correct |
108 ms |
47412 KB |
Output is correct |
| 22 |
Correct |
104 ms |
49860 KB |
Output is correct |
| 23 |
Correct |
71 ms |
47300 KB |
Output is correct |
| 24 |
Correct |
244 ms |
63312 KB |
Output is correct |
| 25 |
Correct |
184 ms |
58408 KB |
Output is correct |
| 26 |
Correct |
205 ms |
61064 KB |
Output is correct |
| 27 |
Correct |
268 ms |
62288 KB |
Output is correct |
