#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
long long d[2007][2007];
long long n,s,f;
int main() {
d[1][1] = 1;
cin >> n >> s >> f;
for(int i=2; i<=n; i++) {
for(int j=0; j<=n; j++) {
if(i==s || i==f) d[i][j] = d[i-1][j]+d[i-1][j-1];
else d[i][j] = d[i-1][j+1]*j + d[i-1][j-1]*(j - int(i>s) - int(i>f));
d[i][j] %= MOD;
}
}
cout << d[n][1] << endl;
return 0;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
0 ms |
204 KB |
Output is correct |
| 2 |
Correct |
1 ms |
332 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
0 ms |
204 KB |
Output is correct |
| 2 |
Correct |
1 ms |
332 KB |
Output is correct |
| 3 |
Correct |
0 ms |
332 KB |
Output is correct |
| 4 |
Correct |
0 ms |
460 KB |
Output is correct |
| 5 |
Correct |
0 ms |
460 KB |
Output is correct |
| 6 |
Correct |
0 ms |
460 KB |
Output is correct |
| 7 |
Correct |
0 ms |
460 KB |
Output is correct |
| 8 |
Correct |
1 ms |
460 KB |
Output is correct |
| 9 |
Correct |
1 ms |
460 KB |
Output is correct |
| 10 |
Correct |
1 ms |
460 KB |
Output is correct |
| 11 |
Correct |
0 ms |
460 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
0 ms |
204 KB |
Output is correct |
| 2 |
Correct |
1 ms |
332 KB |
Output is correct |
| 3 |
Correct |
0 ms |
332 KB |
Output is correct |
| 4 |
Correct |
0 ms |
460 KB |
Output is correct |
| 5 |
Correct |
0 ms |
460 KB |
Output is correct |
| 6 |
Correct |
0 ms |
460 KB |
Output is correct |
| 7 |
Correct |
0 ms |
460 KB |
Output is correct |
| 8 |
Correct |
1 ms |
460 KB |
Output is correct |
| 9 |
Correct |
1 ms |
460 KB |
Output is correct |
| 10 |
Correct |
1 ms |
460 KB |
Output is correct |
| 11 |
Correct |
0 ms |
460 KB |
Output is correct |
| 12 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 13 |
Correct |
1 ms |
1228 KB |
Output is correct |
| 14 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 15 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 16 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 17 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 18 |
Correct |
1 ms |
1228 KB |
Output is correct |
| 19 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 20 |
Correct |
1 ms |
1356 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
0 ms |
204 KB |
Output is correct |
| 2 |
Correct |
1 ms |
332 KB |
Output is correct |
| 3 |
Correct |
0 ms |
332 KB |
Output is correct |
| 4 |
Correct |
0 ms |
460 KB |
Output is correct |
| 5 |
Correct |
0 ms |
460 KB |
Output is correct |
| 6 |
Correct |
0 ms |
460 KB |
Output is correct |
| 7 |
Correct |
0 ms |
460 KB |
Output is correct |
| 8 |
Correct |
1 ms |
460 KB |
Output is correct |
| 9 |
Correct |
1 ms |
460 KB |
Output is correct |
| 10 |
Correct |
1 ms |
460 KB |
Output is correct |
| 11 |
Correct |
0 ms |
460 KB |
Output is correct |
| 12 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 13 |
Correct |
1 ms |
1228 KB |
Output is correct |
| 14 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 15 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 16 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 17 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 18 |
Correct |
1 ms |
1228 KB |
Output is correct |
| 19 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 20 |
Correct |
1 ms |
1356 KB |
Output is correct |
| 21 |
Correct |
4 ms |
6348 KB |
Output is correct |
| 22 |
Correct |
4 ms |
6860 KB |
Output is correct |
| 23 |
Correct |
5 ms |
7756 KB |
Output is correct |
| 24 |
Correct |
24 ms |
31692 KB |
Output is correct |
| 25 |
Correct |
25 ms |
31620 KB |
Output is correct |
| 26 |
Correct |
25 ms |
31784 KB |
Output is correct |
| 27 |
Correct |
25 ms |
31452 KB |
Output is correct |
| 28 |
Correct |
16 ms |
23756 KB |
Output is correct |
