#include <bits/stdc++.h>
using namespace std;
const int MX = 3000;
const long long MOD = 1e9 + 7;
long long dp[MX + 10][MX + 10];
long long calc(long long H, long long W) {
for(int w = 0; w <= W; w++) {
dp[0][w] = 1;
}
for(int h = 0; h <= H; h++) {
dp[h][0] = 1;
}
for(int h = 1; h <= H; h++) {
for(int w = 1; w <= W; w++) {
long long zero = dp[h-1][w];
long long one = 4*w * dp[h-1][w-1] % MOD;
long long two_horiz = 0, two_vert = 0;
if(w >= 2) two_horiz = w*(w - 1) / 2 * dp[h-1][w-2] % MOD;
if(h >= 2) two_vert = w * (h - 1) * dp[h-2][w-1] % MOD;
dp[h][w] = (zero + one + two_horiz + two_vert) % MOD;
}
}
return dp[H][W];
}
int main() {
long long H, W; cin >> H >> W;
cout << (calc(H, W) + MOD - 1) % MOD << endl;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
488 KB |
Output is correct |
3 |
Correct |
2 ms |
564 KB |
Output is correct |
4 |
Correct |
2 ms |
1252 KB |
Output is correct |
5 |
Correct |
2 ms |
1252 KB |
Output is correct |
6 |
Correct |
2 ms |
1556 KB |
Output is correct |
7 |
Correct |
2 ms |
1556 KB |
Output is correct |
8 |
Correct |
3 ms |
1724 KB |
Output is correct |
9 |
Correct |
2 ms |
1724 KB |
Output is correct |
10 |
Correct |
3 ms |
2004 KB |
Output is correct |
11 |
Correct |
2 ms |
2004 KB |
Output is correct |
12 |
Correct |
3 ms |
2388 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
488 KB |
Output is correct |
3 |
Correct |
2 ms |
564 KB |
Output is correct |
4 |
Correct |
2 ms |
1252 KB |
Output is correct |
5 |
Correct |
2 ms |
1252 KB |
Output is correct |
6 |
Correct |
2 ms |
1556 KB |
Output is correct |
7 |
Correct |
2 ms |
1556 KB |
Output is correct |
8 |
Correct |
3 ms |
1724 KB |
Output is correct |
9 |
Correct |
2 ms |
1724 KB |
Output is correct |
10 |
Correct |
3 ms |
2004 KB |
Output is correct |
11 |
Correct |
2 ms |
2004 KB |
Output is correct |
12 |
Correct |
3 ms |
2388 KB |
Output is correct |
13 |
Correct |
2 ms |
2388 KB |
Output is correct |
14 |
Correct |
7 ms |
9940 KB |
Output is correct |
15 |
Correct |
80 ms |
55404 KB |
Output is correct |
16 |
Correct |
7 ms |
55404 KB |
Output is correct |
17 |
Correct |
19 ms |
55404 KB |
Output is correct |
18 |
Correct |
25 ms |
55404 KB |
Output is correct |
19 |
Correct |
91 ms |
63228 KB |
Output is correct |
20 |
Correct |
73 ms |
63228 KB |
Output is correct |
21 |
Correct |
51 ms |
63228 KB |
Output is correct |
22 |
Correct |
51 ms |
63228 KB |
Output is correct |
23 |
Correct |
33 ms |
63228 KB |
Output is correct |
24 |
Correct |
122 ms |
71340 KB |
Output is correct |
25 |
Correct |
92 ms |
71340 KB |
Output is correct |
26 |
Correct |
110 ms |
71340 KB |
Output is correct |
27 |
Correct |
118 ms |
71340 KB |
Output is correct |