#include <stdio.h>
#define N 2000
#define MD 1000000007
int pp2[N * 2 + 1], vv[N * 2 + 1], ff[N * 2 + 1], gg[N * 2 + 1];
void init() {
int i;
pp2[0] = ff[0] = gg[0] = 1;
for (i = 1; i <= N * 2; i++) {
pp2[i] = pp2[i - 1] * 2 % MD;
vv[i] = i == 1 ? 1 : (long long) vv[i - MD % i] * (MD / i + 1) % MD;
ff[i] = (long long) ff[i - 1] * i % MD;
gg[i] = (long long) gg[i - 1] * vv[i] % MD;
}
}
int choose(int n, int k) {
return (long long) ff[n] * gg[k] % MD * gg[n - k] % MD;
}
int main() {
static int dp[N + 1];
int n, n_, m, r, k1, k2, l, l1, l2, x;
init();
scanf("%d%d", &n, &m);
n_ = n * 2;
dp[n] = 1;
for (r = 0; r < m; r++) {
l = (n * 2 + m - 1 - r) / m;
for (k2 = 0; k2 * 2 <= n_; k2++) {
k1 = n_ - k2 * 2, x = dp[k2];
if (x == 0)
continue;
dp[k2] = 0;
for (l2 = 0; l2 <= l && l2 <= k2; l2++) {
l1 = l - l2;
if (l1 >= 0 && l1 <= k1)
dp[k2 - l2] = (dp[k2 - l2] + (long long) x * choose(k1, l1) % MD * choose(k2, l2) % MD * pp2[l2] % MD * ff[l]) % MD;
}
}
n_ -= l;
}
printf("%d\n", dp[0]);
return 0;
}
Compilation message
Main.c: In function 'main':
Main.c:29:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
29 | scanf("%d%d", &n, &m);
| ^~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
0 ms |
340 KB |
Output is correct |
4 |
Correct |
0 ms |
340 KB |
Output is correct |
5 |
Correct |
0 ms |
340 KB |
Output is correct |
6 |
Correct |
0 ms |
340 KB |
Output is correct |
7 |
Correct |
0 ms |
340 KB |
Output is correct |
8 |
Correct |
0 ms |
340 KB |
Output is correct |
9 |
Correct |
0 ms |
340 KB |
Output is correct |
10 |
Correct |
0 ms |
340 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
0 ms |
340 KB |
Output is correct |
4 |
Correct |
0 ms |
340 KB |
Output is correct |
5 |
Correct |
0 ms |
340 KB |
Output is correct |
6 |
Correct |
0 ms |
340 KB |
Output is correct |
7 |
Correct |
0 ms |
340 KB |
Output is correct |
8 |
Correct |
0 ms |
340 KB |
Output is correct |
9 |
Correct |
0 ms |
340 KB |
Output is correct |
10 |
Correct |
0 ms |
340 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
1 ms |
340 KB |
Output is correct |
13 |
Correct |
0 ms |
340 KB |
Output is correct |
14 |
Correct |
0 ms |
340 KB |
Output is correct |
15 |
Correct |
0 ms |
340 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
0 ms |
340 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
1 ms |
340 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
0 ms |
340 KB |
Output is correct |
4 |
Correct |
0 ms |
340 KB |
Output is correct |
5 |
Correct |
0 ms |
340 KB |
Output is correct |
6 |
Correct |
0 ms |
340 KB |
Output is correct |
7 |
Correct |
0 ms |
340 KB |
Output is correct |
8 |
Correct |
0 ms |
340 KB |
Output is correct |
9 |
Correct |
0 ms |
340 KB |
Output is correct |
10 |
Correct |
0 ms |
340 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
1 ms |
340 KB |
Output is correct |
13 |
Correct |
0 ms |
340 KB |
Output is correct |
14 |
Correct |
0 ms |
340 KB |
Output is correct |
15 |
Correct |
0 ms |
340 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
0 ms |
340 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
1 ms |
340 KB |
Output is correct |
20 |
Correct |
1 ms |
340 KB |
Output is correct |
21 |
Correct |
1 ms |
340 KB |
Output is correct |
22 |
Correct |
1 ms |
340 KB |
Output is correct |
23 |
Correct |
1 ms |
340 KB |
Output is correct |
24 |
Correct |
1 ms |
340 KB |
Output is correct |
25 |
Correct |
1 ms |
340 KB |
Output is correct |
26 |
Correct |
1 ms |
340 KB |
Output is correct |
27 |
Correct |
1 ms |
340 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
0 ms |
340 KB |
Output is correct |
4 |
Correct |
0 ms |
340 KB |
Output is correct |
5 |
Correct |
0 ms |
340 KB |
Output is correct |
6 |
Correct |
0 ms |
340 KB |
Output is correct |
7 |
Correct |
0 ms |
340 KB |
Output is correct |
8 |
Correct |
0 ms |
340 KB |
Output is correct |
9 |
Correct |
0 ms |
340 KB |
Output is correct |
10 |
Correct |
0 ms |
340 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
1 ms |
340 KB |
Output is correct |
13 |
Correct |
0 ms |
340 KB |
Output is correct |
14 |
Correct |
0 ms |
340 KB |
Output is correct |
15 |
Correct |
0 ms |
340 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
0 ms |
340 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
1 ms |
340 KB |
Output is correct |
20 |
Correct |
1 ms |
340 KB |
Output is correct |
21 |
Correct |
1 ms |
340 KB |
Output is correct |
22 |
Correct |
1 ms |
340 KB |
Output is correct |
23 |
Correct |
1 ms |
340 KB |
Output is correct |
24 |
Correct |
1 ms |
340 KB |
Output is correct |
25 |
Correct |
1 ms |
340 KB |
Output is correct |
26 |
Correct |
1 ms |
340 KB |
Output is correct |
27 |
Correct |
1 ms |
340 KB |
Output is correct |
28 |
Correct |
3 ms |
340 KB |
Output is correct |
29 |
Correct |
5 ms |
340 KB |
Output is correct |
30 |
Correct |
6 ms |
340 KB |
Output is correct |
31 |
Correct |
3 ms |
340 KB |
Output is correct |
32 |
Correct |
6 ms |
356 KB |
Output is correct |
33 |
Correct |
7 ms |
352 KB |
Output is correct |
34 |
Correct |
10 ms |
340 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
0 ms |
340 KB |
Output is correct |
4 |
Correct |
0 ms |
340 KB |
Output is correct |
5 |
Correct |
0 ms |
340 KB |
Output is correct |
6 |
Correct |
0 ms |
340 KB |
Output is correct |
7 |
Correct |
0 ms |
340 KB |
Output is correct |
8 |
Correct |
0 ms |
340 KB |
Output is correct |
9 |
Correct |
0 ms |
340 KB |
Output is correct |
10 |
Correct |
0 ms |
340 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
1 ms |
340 KB |
Output is correct |
13 |
Correct |
0 ms |
340 KB |
Output is correct |
14 |
Correct |
0 ms |
340 KB |
Output is correct |
15 |
Correct |
0 ms |
340 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
0 ms |
340 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
1 ms |
340 KB |
Output is correct |
20 |
Correct |
1 ms |
340 KB |
Output is correct |
21 |
Correct |
1 ms |
340 KB |
Output is correct |
22 |
Correct |
1 ms |
340 KB |
Output is correct |
23 |
Correct |
1 ms |
340 KB |
Output is correct |
24 |
Correct |
1 ms |
340 KB |
Output is correct |
25 |
Correct |
1 ms |
340 KB |
Output is correct |
26 |
Correct |
1 ms |
340 KB |
Output is correct |
27 |
Correct |
1 ms |
340 KB |
Output is correct |
28 |
Correct |
3 ms |
340 KB |
Output is correct |
29 |
Correct |
5 ms |
340 KB |
Output is correct |
30 |
Correct |
6 ms |
340 KB |
Output is correct |
31 |
Correct |
3 ms |
340 KB |
Output is correct |
32 |
Correct |
6 ms |
356 KB |
Output is correct |
33 |
Correct |
7 ms |
352 KB |
Output is correct |
34 |
Correct |
10 ms |
340 KB |
Output is correct |
35 |
Correct |
17 ms |
340 KB |
Output is correct |
36 |
Correct |
38 ms |
340 KB |
Output is correct |
37 |
Correct |
19 ms |
348 KB |
Output is correct |
38 |
Correct |
28 ms |
340 KB |
Output is correct |
39 |
Correct |
31 ms |
340 KB |
Output is correct |
40 |
Correct |
48 ms |
340 KB |
Output is correct |