#include "bits/stdc++.h"
using namespace std;
#define ar array
const int mod = 1e9 + 7;
int pre[5][5] = {
{0, 2, 2, 2, 2},
{0, 16, 16, 24, 24},
{0, 288, 384, 480, 576},
{0, 9216, 13824, 23040, 26112},
{0, 460800, 829440, 1428480, 2088960}
};
int bp(int a, int b){
int rr = 1;
while(b){
if(b&1) rr = rr * 1ll * a % mod;
a = a * 1ll * a % mod, b >>= 1;
} return rr;
}
signed main(){
ios::sync_with_stdio(0); cin.tie(0);
int n, m; cin>>n>>m;
vector<int> a(m);
for(int i=0;i<2*n;i++){
a[i % m]++;
}
vector<int> dp(2 * n + 1);
vector<int> f(2 * n + 1), inv(2 * n + 1);
f[0] = inv[0] = 1;
for(int i=1;i<=2 * n;i++){
f[i] = f[i-1] * 1ll * i % mod;
inv[i] = bp(f[i], mod - 2);
}
auto C = [&](int n, int k){
return f[n] * 1ll * inv[k] % mod * inv[n - k] % mod;
};
reverse(a.begin(), a.end());
dp[a[0]] = 1;
int sum = a[0];
for(int i=1;i<m;i++){
vector<int> nw(2 * n + 1);
for(int j=0;j<=a[i];j++){
for(int l=j;l<=sum;l++){
nw[l + a[i] - j * 2] = (nw[l + a[i] - 2 * j] + dp[l] * 1ll * f[j] % mod * C(a[i], j) % mod * C(l, j)) % mod;
}
} dp = nw;
sum += a[i];
}
int res = dp[0];
for(int i=0;i<n;i++) res = res * 2ll % mod;
res = res * 1ll * f[n] % mod;
cout<<res<<"\n";
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
312 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
316 KB |
Output is correct |
4 |
Correct |
0 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
6 |
Correct |
1 ms |
204 KB |
Output is correct |
7 |
Correct |
1 ms |
204 KB |
Output is correct |
8 |
Correct |
1 ms |
204 KB |
Output is correct |
9 |
Correct |
1 ms |
204 KB |
Output is correct |
10 |
Correct |
0 ms |
312 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
312 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
316 KB |
Output is correct |
4 |
Correct |
0 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
6 |
Correct |
1 ms |
204 KB |
Output is correct |
7 |
Correct |
1 ms |
204 KB |
Output is correct |
8 |
Correct |
1 ms |
204 KB |
Output is correct |
9 |
Correct |
1 ms |
204 KB |
Output is correct |
10 |
Correct |
0 ms |
312 KB |
Output is correct |
11 |
Correct |
1 ms |
204 KB |
Output is correct |
12 |
Correct |
1 ms |
204 KB |
Output is correct |
13 |
Correct |
1 ms |
308 KB |
Output is correct |
14 |
Correct |
1 ms |
308 KB |
Output is correct |
15 |
Correct |
1 ms |
204 KB |
Output is correct |
16 |
Correct |
1 ms |
204 KB |
Output is correct |
17 |
Correct |
1 ms |
312 KB |
Output is correct |
18 |
Correct |
1 ms |
204 KB |
Output is correct |
19 |
Correct |
1 ms |
204 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
312 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
316 KB |
Output is correct |
4 |
Correct |
0 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
6 |
Correct |
1 ms |
204 KB |
Output is correct |
7 |
Correct |
1 ms |
204 KB |
Output is correct |
8 |
Correct |
1 ms |
204 KB |
Output is correct |
9 |
Correct |
1 ms |
204 KB |
Output is correct |
10 |
Correct |
0 ms |
312 KB |
Output is correct |
11 |
Correct |
1 ms |
204 KB |
Output is correct |
12 |
Correct |
1 ms |
204 KB |
Output is correct |
13 |
Correct |
1 ms |
308 KB |
Output is correct |
14 |
Correct |
1 ms |
308 KB |
Output is correct |
15 |
Correct |
1 ms |
204 KB |
Output is correct |
16 |
Correct |
1 ms |
204 KB |
Output is correct |
17 |
Correct |
1 ms |
312 KB |
Output is correct |
18 |
Correct |
1 ms |
204 KB |
Output is correct |
19 |
Correct |
1 ms |
204 KB |
Output is correct |
20 |
Correct |
1 ms |
312 KB |
Output is correct |
21 |
Correct |
1 ms |
204 KB |
Output is correct |
22 |
Correct |
4 ms |
204 KB |
Output is correct |
23 |
Correct |
2 ms |
316 KB |
Output is correct |
24 |
Correct |
5 ms |
204 KB |
Output is correct |
25 |
Correct |
3 ms |
308 KB |
Output is correct |
26 |
Correct |
3 ms |
204 KB |
Output is correct |
27 |
Correct |
5 ms |
204 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
312 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
316 KB |
Output is correct |
4 |
Correct |
0 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
6 |
Correct |
1 ms |
204 KB |
Output is correct |
7 |
Correct |
1 ms |
204 KB |
Output is correct |
8 |
Correct |
1 ms |
204 KB |
Output is correct |
9 |
Correct |
1 ms |
204 KB |
Output is correct |
10 |
Correct |
0 ms |
312 KB |
Output is correct |
11 |
Correct |
1 ms |
204 KB |
Output is correct |
12 |
Correct |
1 ms |
204 KB |
Output is correct |
13 |
Correct |
1 ms |
308 KB |
Output is correct |
14 |
Correct |
1 ms |
308 KB |
Output is correct |
15 |
Correct |
1 ms |
204 KB |
Output is correct |
16 |
Correct |
1 ms |
204 KB |
Output is correct |
17 |
Correct |
1 ms |
312 KB |
Output is correct |
18 |
Correct |
1 ms |
204 KB |
Output is correct |
19 |
Correct |
1 ms |
204 KB |
Output is correct |
20 |
Correct |
1 ms |
312 KB |
Output is correct |
21 |
Correct |
1 ms |
204 KB |
Output is correct |
22 |
Correct |
4 ms |
204 KB |
Output is correct |
23 |
Correct |
2 ms |
316 KB |
Output is correct |
24 |
Correct |
5 ms |
204 KB |
Output is correct |
25 |
Correct |
3 ms |
308 KB |
Output is correct |
26 |
Correct |
3 ms |
204 KB |
Output is correct |
27 |
Correct |
5 ms |
204 KB |
Output is correct |
28 |
Correct |
14 ms |
312 KB |
Output is correct |
29 |
Correct |
17 ms |
332 KB |
Output is correct |
30 |
Correct |
19 ms |
332 KB |
Output is correct |
31 |
Correct |
11 ms |
324 KB |
Output is correct |
32 |
Correct |
17 ms |
332 KB |
Output is correct |
33 |
Correct |
21 ms |
340 KB |
Output is correct |
34 |
Correct |
40 ms |
312 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
312 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
316 KB |
Output is correct |
4 |
Correct |
0 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
6 |
Correct |
1 ms |
204 KB |
Output is correct |
7 |
Correct |
1 ms |
204 KB |
Output is correct |
8 |
Correct |
1 ms |
204 KB |
Output is correct |
9 |
Correct |
1 ms |
204 KB |
Output is correct |
10 |
Correct |
0 ms |
312 KB |
Output is correct |
11 |
Correct |
1 ms |
204 KB |
Output is correct |
12 |
Correct |
1 ms |
204 KB |
Output is correct |
13 |
Correct |
1 ms |
308 KB |
Output is correct |
14 |
Correct |
1 ms |
308 KB |
Output is correct |
15 |
Correct |
1 ms |
204 KB |
Output is correct |
16 |
Correct |
1 ms |
204 KB |
Output is correct |
17 |
Correct |
1 ms |
312 KB |
Output is correct |
18 |
Correct |
1 ms |
204 KB |
Output is correct |
19 |
Correct |
1 ms |
204 KB |
Output is correct |
20 |
Correct |
1 ms |
312 KB |
Output is correct |
21 |
Correct |
1 ms |
204 KB |
Output is correct |
22 |
Correct |
4 ms |
204 KB |
Output is correct |
23 |
Correct |
2 ms |
316 KB |
Output is correct |
24 |
Correct |
5 ms |
204 KB |
Output is correct |
25 |
Correct |
3 ms |
308 KB |
Output is correct |
26 |
Correct |
3 ms |
204 KB |
Output is correct |
27 |
Correct |
5 ms |
204 KB |
Output is correct |
28 |
Correct |
14 ms |
312 KB |
Output is correct |
29 |
Correct |
17 ms |
332 KB |
Output is correct |
30 |
Correct |
19 ms |
332 KB |
Output is correct |
31 |
Correct |
11 ms |
324 KB |
Output is correct |
32 |
Correct |
17 ms |
332 KB |
Output is correct |
33 |
Correct |
21 ms |
340 KB |
Output is correct |
34 |
Correct |
40 ms |
312 KB |
Output is correct |
35 |
Correct |
66 ms |
344 KB |
Output is correct |
36 |
Correct |
140 ms |
356 KB |
Output is correct |
37 |
Correct |
69 ms |
344 KB |
Output is correct |
38 |
Correct |
96 ms |
332 KB |
Output is correct |
39 |
Correct |
107 ms |
348 KB |
Output is correct |
40 |
Correct |
177 ms |
368 KB |
Output is correct |