#include <bits/stdc++.h>
using namespace std;
const int mod=1e9+7;
const int N=2005;
int add(int x, int y){ x+=y;return x>=mod?x-mod:x;}
void ADD(int &x, int y){ x=add(x,y);}
int sub(int x, int y){ x-=y;return x<0?x+mod:x;}
void SUB(int &x, int y){ x=sub(x,y);}
int dp[2][N][N],sum[2][N][N];
int Get(int i, int l, int r, int t)
{
if(i>=l && r>=i) return add(sub(sum[t][i-1][i-1],sum[t][i-1][l-1]),sub(sum[t][i][r],sum[t][i][i]));
else if(i>r) return sub(sum[t][i-1][r],sum[t][i-1][l-1]);
else return sub(sum[t][i][r],sum[t][i][l-1]);
}
int main()
{
int n,cs,cf;
scanf("%i %i %i",&n,&cs,&cf);
dp[0][1][1]=dp[1][1][1]=1;
for(int l=2;l<=n;l++)
{
for(int t=0;t<2;t++)
for(int i=1;i<=l;i++)
for(int j=1;j<=l;j++)
{
if(t==0) for(int k=1;k<=j;k++) ADD(sum[t^1][i+(k<=i)][k],dp[t][i][j]);
else for(int k=j+1;k<=l;k++) ADD(sum[t^1][i+(k<=i)][k],dp[t][i][j]);
}
for(int t=0;t<2;t++)
for(int i=1;i<=l;i++)
for(int j=1;j<=l;j++)
dp[t][i][j]=sum[t][i][j],sum[t][i][j]=0;
}
int ans=add(dp[0][cs][cf],dp[1][cs][cf]);
printf("%i\n",ans);
return 0;
}
Compilation message
kangaroo.cpp: In function 'int main()':
kangaroo.cpp:19:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%i %i %i",&n,&cs,&cf);
~~~~~^~~~~~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
376 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
376 KB |
Output is correct |
3 |
Correct |
3 ms |
760 KB |
Output is correct |
4 |
Correct |
4 ms |
1016 KB |
Output is correct |
5 |
Correct |
4 ms |
1016 KB |
Output is correct |
6 |
Correct |
4 ms |
988 KB |
Output is correct |
7 |
Correct |
4 ms |
1016 KB |
Output is correct |
8 |
Correct |
4 ms |
1016 KB |
Output is correct |
9 |
Correct |
5 ms |
1144 KB |
Output is correct |
10 |
Correct |
5 ms |
1016 KB |
Output is correct |
11 |
Correct |
4 ms |
1016 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
376 KB |
Output is correct |
3 |
Correct |
3 ms |
760 KB |
Output is correct |
4 |
Correct |
4 ms |
1016 KB |
Output is correct |
5 |
Correct |
4 ms |
1016 KB |
Output is correct |
6 |
Correct |
4 ms |
988 KB |
Output is correct |
7 |
Correct |
4 ms |
1016 KB |
Output is correct |
8 |
Correct |
4 ms |
1016 KB |
Output is correct |
9 |
Correct |
5 ms |
1144 KB |
Output is correct |
10 |
Correct |
5 ms |
1016 KB |
Output is correct |
11 |
Correct |
4 ms |
1016 KB |
Output is correct |
12 |
Correct |
954 ms |
4204 KB |
Output is correct |
13 |
Correct |
768 ms |
4092 KB |
Output is correct |
14 |
Correct |
943 ms |
4344 KB |
Output is correct |
15 |
Correct |
960 ms |
4292 KB |
Output is correct |
16 |
Correct |
972 ms |
4264 KB |
Output is correct |
17 |
Correct |
968 ms |
4256 KB |
Output is correct |
18 |
Correct |
611 ms |
3636 KB |
Output is correct |
19 |
Correct |
942 ms |
4128 KB |
Output is correct |
20 |
Correct |
993 ms |
4304 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
376 KB |
Output is correct |
3 |
Correct |
3 ms |
760 KB |
Output is correct |
4 |
Correct |
4 ms |
1016 KB |
Output is correct |
5 |
Correct |
4 ms |
1016 KB |
Output is correct |
6 |
Correct |
4 ms |
988 KB |
Output is correct |
7 |
Correct |
4 ms |
1016 KB |
Output is correct |
8 |
Correct |
4 ms |
1016 KB |
Output is correct |
9 |
Correct |
5 ms |
1144 KB |
Output is correct |
10 |
Correct |
5 ms |
1016 KB |
Output is correct |
11 |
Correct |
4 ms |
1016 KB |
Output is correct |
12 |
Correct |
954 ms |
4204 KB |
Output is correct |
13 |
Correct |
768 ms |
4092 KB |
Output is correct |
14 |
Correct |
943 ms |
4344 KB |
Output is correct |
15 |
Correct |
960 ms |
4292 KB |
Output is correct |
16 |
Correct |
972 ms |
4264 KB |
Output is correct |
17 |
Correct |
968 ms |
4256 KB |
Output is correct |
18 |
Correct |
611 ms |
3636 KB |
Output is correct |
19 |
Correct |
942 ms |
4128 KB |
Output is correct |
20 |
Correct |
993 ms |
4304 KB |
Output is correct |
21 |
Execution timed out |
2061 ms |
5328 KB |
Time limit exceeded |
22 |
Halted |
0 ms |
0 KB |
- |