///
/// You fell for it, fool!
/// Thunder Cross Split Attack!
///
#include <bits/stdc++.h>
#define Loop(x,l,r) for(ll x = ll(l); x < ll(r); ++x)
typedef long long ll;
using namespace std;
const int mod = 1e9+7;
const int N = 3010;
ll dp[N][N];
int n, m;
int main()
{
ios::sync_with_stdio(false); cin.tie(0);
cin >> n >> m;
Loop(i,0,N) dp[0][i] = dp[i][0] = 1;
Loop(x,1,N) Loop(y,1,N)
{
dp[x][y] = dp[x-1][y];
dp[x][y] += 4*y*dp[x-1][y-1] % mod;
if(y>1) dp[x][y] += y*(y-1)/2*dp[x-1][y-2] % mod;
if(x>1) dp[x][y] += y*(x-1)*dp[x-2][y-1] % mod;
dp[x][y] %= mod;
}
cout << (dp[n][m]+mod-1)%mod << '\n';
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
84 ms |
71288 KB |
Output is correct |
2 |
Correct |
87 ms |
71184 KB |
Output is correct |
3 |
Correct |
86 ms |
71108 KB |
Output is correct |
4 |
Correct |
85 ms |
71188 KB |
Output is correct |
5 |
Correct |
87 ms |
71260 KB |
Output is correct |
6 |
Correct |
84 ms |
71192 KB |
Output is correct |
7 |
Correct |
86 ms |
71196 KB |
Output is correct |
8 |
Correct |
87 ms |
71196 KB |
Output is correct |
9 |
Correct |
86 ms |
71164 KB |
Output is correct |
10 |
Correct |
85 ms |
71128 KB |
Output is correct |
11 |
Correct |
86 ms |
71408 KB |
Output is correct |
12 |
Correct |
84 ms |
71128 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
84 ms |
71288 KB |
Output is correct |
2 |
Correct |
87 ms |
71184 KB |
Output is correct |
3 |
Correct |
86 ms |
71108 KB |
Output is correct |
4 |
Correct |
85 ms |
71188 KB |
Output is correct |
5 |
Correct |
87 ms |
71260 KB |
Output is correct |
6 |
Correct |
84 ms |
71192 KB |
Output is correct |
7 |
Correct |
86 ms |
71196 KB |
Output is correct |
8 |
Correct |
87 ms |
71196 KB |
Output is correct |
9 |
Correct |
86 ms |
71164 KB |
Output is correct |
10 |
Correct |
85 ms |
71128 KB |
Output is correct |
11 |
Correct |
86 ms |
71408 KB |
Output is correct |
12 |
Correct |
84 ms |
71128 KB |
Output is correct |
13 |
Correct |
87 ms |
71224 KB |
Output is correct |
14 |
Correct |
86 ms |
71108 KB |
Output is correct |
15 |
Correct |
85 ms |
71144 KB |
Output is correct |
16 |
Correct |
92 ms |
71328 KB |
Output is correct |
17 |
Correct |
85 ms |
71116 KB |
Output is correct |
18 |
Correct |
87 ms |
71128 KB |
Output is correct |
19 |
Correct |
85 ms |
71104 KB |
Output is correct |
20 |
Correct |
87 ms |
71160 KB |
Output is correct |
21 |
Correct |
85 ms |
71112 KB |
Output is correct |
22 |
Correct |
90 ms |
71236 KB |
Output is correct |
23 |
Correct |
85 ms |
71108 KB |
Output is correct |
24 |
Correct |
86 ms |
71204 KB |
Output is correct |
25 |
Correct |
87 ms |
71212 KB |
Output is correct |
26 |
Correct |
89 ms |
71188 KB |
Output is correct |
27 |
Correct |
85 ms |
71208 KB |
Output is correct |