#include<bits/stdc++.h>
using namespace std;
const int N=2005;
const int MOD=1000000007;
int dp[N][N];
inline void trans(long long val,int id,int col){
if(col<0)
return;
val%=MOD;
dp[id][col]+=val;
if(dp[id][col]>MOD)
dp[id][col]-=MOD;
}
int main()
{
int n,cs,cf;
scanf("%d%d%d",&n,&cs,&cf);
if(cf<cs)
swap(cf,cs);
dp[1][0]=1;
for(int i=1;i<cs;i++){
for(int j=0;j<i;j++){
trans(dp[i][j],i+1,j+1);
trans(1LL*dp[i][j]*(j-1)*j,i+1,j-1);
}
}
for(int j=0;j<cs;j++){
trans(dp[cs][j],cs+1,j);
trans(1LL*dp[cs][j]*j,cs+1,j-1);
}
for(int i=cs+1;i<cf;i++){
for(int j=0;j<i;j++){
trans(dp[i][j],i+1,j+1);
trans(1LL*dp[i][j]*(j)*j,i+1,j-1);
}
}
for(int j=0;j<cf;j++){
trans(dp[cf][j],cf+1,j);
trans(1LL*dp[cf][j]*j,cf+1,j-1);
}
for(int i=cf+1;i<=n;i++){
for(int j=0;j<i;j++){
trans(dp[i][j],i+1,j+1);
trans(1LL*dp[i][j]*(j+1)*j,i+1,j-1);
}
}
printf("%d",dp[n][0]);
return 0;
}
Compilation message
kangaroo.cpp: In function 'int main()':
kangaroo.cpp:17:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
17 | scanf("%d%d%d",&n,&cs,&cf);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
384 KB |
Output is correct |
2 |
Correct |
1 ms |
384 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
384 KB |
Output is correct |
2 |
Correct |
1 ms |
384 KB |
Output is correct |
3 |
Correct |
1 ms |
384 KB |
Output is correct |
4 |
Correct |
1 ms |
512 KB |
Output is correct |
5 |
Correct |
1 ms |
512 KB |
Output is correct |
6 |
Correct |
1 ms |
512 KB |
Output is correct |
7 |
Correct |
1 ms |
512 KB |
Output is correct |
8 |
Correct |
1 ms |
512 KB |
Output is correct |
9 |
Correct |
1 ms |
512 KB |
Output is correct |
10 |
Correct |
1 ms |
512 KB |
Output is correct |
11 |
Correct |
1 ms |
512 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
384 KB |
Output is correct |
2 |
Correct |
1 ms |
384 KB |
Output is correct |
3 |
Correct |
1 ms |
384 KB |
Output is correct |
4 |
Correct |
1 ms |
512 KB |
Output is correct |
5 |
Correct |
1 ms |
512 KB |
Output is correct |
6 |
Correct |
1 ms |
512 KB |
Output is correct |
7 |
Correct |
1 ms |
512 KB |
Output is correct |
8 |
Correct |
1 ms |
512 KB |
Output is correct |
9 |
Correct |
1 ms |
512 KB |
Output is correct |
10 |
Correct |
1 ms |
512 KB |
Output is correct |
11 |
Correct |
1 ms |
512 KB |
Output is correct |
12 |
Correct |
1 ms |
1152 KB |
Output is correct |
13 |
Correct |
1 ms |
1148 KB |
Output is correct |
14 |
Correct |
1 ms |
1152 KB |
Output is correct |
15 |
Correct |
1 ms |
1152 KB |
Output is correct |
16 |
Correct |
1 ms |
1152 KB |
Output is correct |
17 |
Correct |
2 ms |
1152 KB |
Output is correct |
18 |
Correct |
1 ms |
1152 KB |
Output is correct |
19 |
Correct |
1 ms |
1152 KB |
Output is correct |
20 |
Correct |
1 ms |
1152 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
384 KB |
Output is correct |
2 |
Correct |
1 ms |
384 KB |
Output is correct |
3 |
Correct |
1 ms |
384 KB |
Output is correct |
4 |
Correct |
1 ms |
512 KB |
Output is correct |
5 |
Correct |
1 ms |
512 KB |
Output is correct |
6 |
Correct |
1 ms |
512 KB |
Output is correct |
7 |
Correct |
1 ms |
512 KB |
Output is correct |
8 |
Correct |
1 ms |
512 KB |
Output is correct |
9 |
Correct |
1 ms |
512 KB |
Output is correct |
10 |
Correct |
1 ms |
512 KB |
Output is correct |
11 |
Correct |
1 ms |
512 KB |
Output is correct |
12 |
Correct |
1 ms |
1152 KB |
Output is correct |
13 |
Correct |
1 ms |
1148 KB |
Output is correct |
14 |
Correct |
1 ms |
1152 KB |
Output is correct |
15 |
Correct |
1 ms |
1152 KB |
Output is correct |
16 |
Correct |
1 ms |
1152 KB |
Output is correct |
17 |
Correct |
2 ms |
1152 KB |
Output is correct |
18 |
Correct |
1 ms |
1152 KB |
Output is correct |
19 |
Correct |
1 ms |
1152 KB |
Output is correct |
20 |
Correct |
1 ms |
1152 KB |
Output is correct |
21 |
Correct |
4 ms |
3840 KB |
Output is correct |
22 |
Correct |
6 ms |
4096 KB |
Output is correct |
23 |
Correct |
5 ms |
4480 KB |
Output is correct |
24 |
Correct |
22 ms |
14080 KB |
Output is correct |
25 |
Correct |
22 ms |
14072 KB |
Output is correct |
26 |
Correct |
22 ms |
14072 KB |
Output is correct |
27 |
Correct |
21 ms |
14080 KB |
Output is correct |
28 |
Correct |
14 ms |
10240 KB |
Output is correct |