#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int MAXN = 3018, MOD = 1e9 + 7;
#define debug(...) fprintf(stderr, __VA_ARGS__)
#define fi first
#define se second
#define all(v) (v).begin(), (v).end()
#define fillchar(a, s) memset((a), (s), sizeof(a))
void addeq (int &x, int y) {
x += y;
if (x >= MOD) {
x -= MOD;
}
}
int mult (int x, int y) {
return ll(x) * y % MOD;
}
int N, M;
int dp[MAXN][MAXN];
int main() {
scanf("%d %d", &N, &M);
for (int j = 0; j <= M; j++) {
dp[0][j] = 1;
}
for (int i = 0; i <= N; i++) {
dp[i][0] = 1;
}
for (int i = 1; i <= N; i++) {
for (int j = 1; j <= M; j++) {
int &ref = dp[i][j];
addeq(ref, mult(4 * j, dp[i - 1][j - 1])); //put one on this row
addeq(ref, dp[i - 1][j]); //put nothing on this row
if (j > 1) {
addeq(ref, mult(j * (j - 1) / 2, dp[i - 1][j - 2])); //2 points on the same row
}
if (i > 1) {
addeq(ref, mult((i - 1) * j, dp[i - 2][j - 1]));
}
}
}
printf("%d\n", dp[N][M] - 1);
}
Compilation message
tents.cpp: In function 'int main()':
tents.cpp:31:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &N, &M);
~~~~~^~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
248 KB |
Output is correct |
2 |
Correct |
2 ms |
488 KB |
Output is correct |
3 |
Correct |
2 ms |
576 KB |
Output is correct |
4 |
Correct |
3 ms |
1252 KB |
Output is correct |
5 |
Correct |
3 ms |
1252 KB |
Output is correct |
6 |
Correct |
3 ms |
1432 KB |
Output is correct |
7 |
Correct |
3 ms |
1432 KB |
Output is correct |
8 |
Correct |
4 ms |
1544 KB |
Output is correct |
9 |
Correct |
3 ms |
1544 KB |
Output is correct |
10 |
Correct |
5 ms |
1904 KB |
Output is correct |
11 |
Correct |
2 ms |
1904 KB |
Output is correct |
12 |
Correct |
5 ms |
2060 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
248 KB |
Output is correct |
2 |
Correct |
2 ms |
488 KB |
Output is correct |
3 |
Correct |
2 ms |
576 KB |
Output is correct |
4 |
Correct |
3 ms |
1252 KB |
Output is correct |
5 |
Correct |
3 ms |
1252 KB |
Output is correct |
6 |
Correct |
3 ms |
1432 KB |
Output is correct |
7 |
Correct |
3 ms |
1432 KB |
Output is correct |
8 |
Correct |
4 ms |
1544 KB |
Output is correct |
9 |
Correct |
3 ms |
1544 KB |
Output is correct |
10 |
Correct |
5 ms |
1904 KB |
Output is correct |
11 |
Correct |
2 ms |
1904 KB |
Output is correct |
12 |
Correct |
5 ms |
2060 KB |
Output is correct |
13 |
Correct |
2 ms |
2060 KB |
Output is correct |
14 |
Correct |
9 ms |
9880 KB |
Output is correct |
15 |
Correct |
101 ms |
33284 KB |
Output is correct |
16 |
Correct |
11 ms |
33284 KB |
Output is correct |
17 |
Correct |
23 ms |
33284 KB |
Output is correct |
18 |
Correct |
28 ms |
33284 KB |
Output is correct |
19 |
Correct |
106 ms |
34948 KB |
Output is correct |
20 |
Correct |
86 ms |
34948 KB |
Output is correct |
21 |
Correct |
60 ms |
34948 KB |
Output is correct |
22 |
Correct |
62 ms |
34948 KB |
Output is correct |
23 |
Correct |
37 ms |
34948 KB |
Output is correct |
24 |
Correct |
146 ms |
36036 KB |
Output is correct |
25 |
Correct |
107 ms |
36036 KB |
Output is correct |
26 |
Correct |
117 ms |
36036 KB |
Output is correct |
27 |
Correct |
124 ms |
36036 KB |
Output is correct |