#include <iostream>
using namespace std;
using ll = long long;
const ll MOD = 1000000007;
const ll MAXN = 2077;
ll pw(ll a, ll m) {
if (!m)
return 1;
a %= MOD;
if (m % 2)
return a * pw(a, m - 1) % MOD;
return pw(a * a, m / 2);
}
ll fact[MAXN];
ll rfact[MAXN];
//ll choose(ll n, ll k) {
//if (n < 0 || k < 0 || k > n)
//return 0;
//return
//}
ll dp[MAXN][MAXN];
ll choose[MAXN][MAXN];
signed main() {
fact[0] = rfact[0] = 1;
for (int i = 1; i < MAXN; ++i) {
fact[i] = (fact[i - 1] * i) % MOD;
rfact[i] = pw(fact[i], MOD - 2);
}
for (int i = 0; i < MAXN; ++i) {
for (int j = 0; j <= i; ++j) {
choose[i][j] = (fact[i] * rfact[j] % MOD) * rfact[i - j] % MOD;
}
}
int n, m;
cin >> n >> m;
if (m == 1) {
cout << 0 << endl;
return 0;
}
int sz = 2 * n / m;
int szinc = 2 * n % m;
int smsz = sz + int(0 < szinc);
dp[0][0] = choose[n][smsz] * pw(2, n) % MOD;
for (int i = 0; i < m; ++i) {
dp[0][0] *= fact[sz + int(i < szinc)];
dp[0][0] %= MOD;
}
for (int i = 1; i < m; ++i) {
int szi = sz + int(i < szinc);
for (int c = 0; c <= n; ++c) {
for (int cp = 0; cp <= c; ++cp) {
ll cnt1 = smsz - cp * 2;
ll cnt0 = n + cp - smsz;
if (cnt1 < 0 || cnt0 < 0 || szi - (c - cp) < 0)
continue;
dp[i][c] += (dp[i - 1][cp] * choose[cnt1][c - cp] % MOD) * choose[cnt0][szi - (c - cp)];
dp[i][c] %= MOD;
}
//cout << dp[i][c] << ' ';
}
smsz += szi;
//cout << endl;
}
cout << dp[m - 1][n] % MOD << endl;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
24524 KB |
Output is correct |
2 |
Correct |
20 ms |
24488 KB |
Output is correct |
3 |
Correct |
16 ms |
24464 KB |
Output is correct |
4 |
Correct |
16 ms |
24524 KB |
Output is correct |
5 |
Correct |
17 ms |
24464 KB |
Output is correct |
6 |
Correct |
17 ms |
24480 KB |
Output is correct |
7 |
Correct |
17 ms |
24532 KB |
Output is correct |
8 |
Correct |
20 ms |
24524 KB |
Output is correct |
9 |
Correct |
22 ms |
24524 KB |
Output is correct |
10 |
Correct |
15 ms |
24468 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
24524 KB |
Output is correct |
2 |
Correct |
20 ms |
24488 KB |
Output is correct |
3 |
Correct |
16 ms |
24464 KB |
Output is correct |
4 |
Correct |
16 ms |
24524 KB |
Output is correct |
5 |
Correct |
17 ms |
24464 KB |
Output is correct |
6 |
Correct |
17 ms |
24480 KB |
Output is correct |
7 |
Correct |
17 ms |
24532 KB |
Output is correct |
8 |
Correct |
20 ms |
24524 KB |
Output is correct |
9 |
Correct |
22 ms |
24524 KB |
Output is correct |
10 |
Correct |
15 ms |
24468 KB |
Output is correct |
11 |
Correct |
17 ms |
24752 KB |
Output is correct |
12 |
Correct |
17 ms |
24696 KB |
Output is correct |
13 |
Correct |
16 ms |
24476 KB |
Output is correct |
14 |
Correct |
16 ms |
24636 KB |
Output is correct |
15 |
Correct |
16 ms |
24772 KB |
Output is correct |
16 |
Correct |
16 ms |
24472 KB |
Output is correct |
17 |
Correct |
17 ms |
24636 KB |
Output is correct |
18 |
Correct |
17 ms |
24652 KB |
Output is correct |
19 |
Correct |
20 ms |
24484 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
24524 KB |
Output is correct |
2 |
Correct |
20 ms |
24488 KB |
Output is correct |
3 |
Correct |
16 ms |
24464 KB |
Output is correct |
4 |
Correct |
16 ms |
24524 KB |
Output is correct |
5 |
Correct |
17 ms |
24464 KB |
Output is correct |
6 |
Correct |
17 ms |
24480 KB |
Output is correct |
7 |
Correct |
17 ms |
24532 KB |
Output is correct |
8 |
Correct |
20 ms |
24524 KB |
Output is correct |
9 |
Correct |
22 ms |
24524 KB |
Output is correct |
10 |
Correct |
15 ms |
24468 KB |
Output is correct |
11 |
Correct |
17 ms |
24752 KB |
Output is correct |
12 |
Correct |
17 ms |
24696 KB |
Output is correct |
13 |
Correct |
16 ms |
24476 KB |
Output is correct |
14 |
Correct |
16 ms |
24636 KB |
Output is correct |
15 |
Correct |
16 ms |
24772 KB |
Output is correct |
16 |
Correct |
16 ms |
24472 KB |
Output is correct |
17 |
Correct |
17 ms |
24636 KB |
Output is correct |
18 |
Correct |
17 ms |
24652 KB |
Output is correct |
19 |
Correct |
20 ms |
24484 KB |
Output is correct |
20 |
Correct |
17 ms |
24608 KB |
Output is correct |
21 |
Correct |
20 ms |
24856 KB |
Output is correct |
22 |
Correct |
29 ms |
25664 KB |
Output is correct |
23 |
Correct |
17 ms |
24524 KB |
Output is correct |
24 |
Correct |
25 ms |
25156 KB |
Output is correct |
25 |
Correct |
29 ms |
25628 KB |
Output is correct |
26 |
Correct |
17 ms |
24512 KB |
Output is correct |
27 |
Correct |
35 ms |
25804 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
24524 KB |
Output is correct |
2 |
Correct |
20 ms |
24488 KB |
Output is correct |
3 |
Correct |
16 ms |
24464 KB |
Output is correct |
4 |
Correct |
16 ms |
24524 KB |
Output is correct |
5 |
Correct |
17 ms |
24464 KB |
Output is correct |
6 |
Correct |
17 ms |
24480 KB |
Output is correct |
7 |
Correct |
17 ms |
24532 KB |
Output is correct |
8 |
Correct |
20 ms |
24524 KB |
Output is correct |
9 |
Correct |
22 ms |
24524 KB |
Output is correct |
10 |
Correct |
15 ms |
24468 KB |
Output is correct |
11 |
Correct |
17 ms |
24752 KB |
Output is correct |
12 |
Correct |
17 ms |
24696 KB |
Output is correct |
13 |
Correct |
16 ms |
24476 KB |
Output is correct |
14 |
Correct |
16 ms |
24636 KB |
Output is correct |
15 |
Correct |
16 ms |
24772 KB |
Output is correct |
16 |
Correct |
16 ms |
24472 KB |
Output is correct |
17 |
Correct |
17 ms |
24636 KB |
Output is correct |
18 |
Correct |
17 ms |
24652 KB |
Output is correct |
19 |
Correct |
20 ms |
24484 KB |
Output is correct |
20 |
Correct |
17 ms |
24608 KB |
Output is correct |
21 |
Correct |
20 ms |
24856 KB |
Output is correct |
22 |
Correct |
29 ms |
25664 KB |
Output is correct |
23 |
Correct |
17 ms |
24524 KB |
Output is correct |
24 |
Correct |
25 ms |
25156 KB |
Output is correct |
25 |
Correct |
29 ms |
25628 KB |
Output is correct |
26 |
Correct |
17 ms |
24512 KB |
Output is correct |
27 |
Correct |
35 ms |
25804 KB |
Output is correct |
28 |
Correct |
25 ms |
24636 KB |
Output is correct |
29 |
Correct |
111 ms |
26188 KB |
Output is correct |
30 |
Correct |
205 ms |
27652 KB |
Output is correct |
31 |
Correct |
26 ms |
24524 KB |
Output is correct |
32 |
Correct |
120 ms |
26308 KB |
Output is correct |
33 |
Correct |
254 ms |
27992 KB |
Output is correct |
34 |
Correct |
500 ms |
29796 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
24524 KB |
Output is correct |
2 |
Correct |
20 ms |
24488 KB |
Output is correct |
3 |
Correct |
16 ms |
24464 KB |
Output is correct |
4 |
Correct |
16 ms |
24524 KB |
Output is correct |
5 |
Correct |
17 ms |
24464 KB |
Output is correct |
6 |
Correct |
17 ms |
24480 KB |
Output is correct |
7 |
Correct |
17 ms |
24532 KB |
Output is correct |
8 |
Correct |
20 ms |
24524 KB |
Output is correct |
9 |
Correct |
22 ms |
24524 KB |
Output is correct |
10 |
Correct |
15 ms |
24468 KB |
Output is correct |
11 |
Correct |
17 ms |
24752 KB |
Output is correct |
12 |
Correct |
17 ms |
24696 KB |
Output is correct |
13 |
Correct |
16 ms |
24476 KB |
Output is correct |
14 |
Correct |
16 ms |
24636 KB |
Output is correct |
15 |
Correct |
16 ms |
24772 KB |
Output is correct |
16 |
Correct |
16 ms |
24472 KB |
Output is correct |
17 |
Correct |
17 ms |
24636 KB |
Output is correct |
18 |
Correct |
17 ms |
24652 KB |
Output is correct |
19 |
Correct |
20 ms |
24484 KB |
Output is correct |
20 |
Correct |
17 ms |
24608 KB |
Output is correct |
21 |
Correct |
20 ms |
24856 KB |
Output is correct |
22 |
Correct |
29 ms |
25664 KB |
Output is correct |
23 |
Correct |
17 ms |
24524 KB |
Output is correct |
24 |
Correct |
25 ms |
25156 KB |
Output is correct |
25 |
Correct |
29 ms |
25628 KB |
Output is correct |
26 |
Correct |
17 ms |
24512 KB |
Output is correct |
27 |
Correct |
35 ms |
25804 KB |
Output is correct |
28 |
Correct |
25 ms |
24636 KB |
Output is correct |
29 |
Correct |
111 ms |
26188 KB |
Output is correct |
30 |
Correct |
205 ms |
27652 KB |
Output is correct |
31 |
Correct |
26 ms |
24524 KB |
Output is correct |
32 |
Correct |
120 ms |
26308 KB |
Output is correct |
33 |
Correct |
254 ms |
27992 KB |
Output is correct |
34 |
Correct |
500 ms |
29796 KB |
Output is correct |
35 |
Correct |
53 ms |
24604 KB |
Output is correct |
36 |
Execution timed out |
1086 ms |
28600 KB |
Time limit exceeded |
37 |
Halted |
0 ms |
0 KB |
- |