#include <bits/stdc++.h>
#define DIM 210
#define MOD 1000000007
using namespace std;
int dp[DIM][DIM][DIM][2];
int n,i,j,k,t,st,fn;
int _(int x){
while (x < 0)
x += MOD;
while (x >= MOD)
x -= MOD;
return x;
}
int main (){
// ifstream cin ("kangaroo.in");
// ofstream cout ("kangaroo.out");
cin>>n>>st>>fn;
/// dp[i][j][k][0/1] - nr de permutari de lg i care incep pe j si se termina pe k si sa inceapa crescator / descrescator
dp[2][1][2][0] = dp[2][2][1][1] = 1;
for (i=3;i<=n;i++){
for (j=1;j<=i;j++){
for (k=j+1;k<=i;k++){
if (j == 1){
for (t=2;t<=i;t++)
dp[i][j][k][0] = _(dp[i][j][k][0] + dp[i-1][t][k-1][1]);
} else dp[i][j][k][0] = _(dp[i][j-1][k][0] - dp[i-1][j-1][k-1][1]);
dp[i][j][k][1] = _(dp[i][j-1][k][1] + dp[i-1][j-1][k-1][0]);
if (i%2)
dp[i][k][j][0] = dp[i][j][k][0], dp[i][k][j][1] = dp[i][j][k][1];
else dp[i][k][j][0] = dp[i][j][k][1], dp[i][k][j][1] = dp[i][j][k][0];
}
}
}
if (st > fn)
swap (st,fn);
cout<<_(dp[n][st][fn][0] + dp[n][st][fn][1]);
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
384 KB |
Output is correct |
2 |
Correct |
5 ms |
384 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
384 KB |
Output is correct |
2 |
Correct |
5 ms |
384 KB |
Output is correct |
3 |
Correct |
5 ms |
896 KB |
Output is correct |
4 |
Correct |
5 ms |
1792 KB |
Output is correct |
5 |
Correct |
6 ms |
1664 KB |
Output is correct |
6 |
Correct |
5 ms |
1792 KB |
Output is correct |
7 |
Correct |
5 ms |
1536 KB |
Output is correct |
8 |
Correct |
5 ms |
1664 KB |
Output is correct |
9 |
Correct |
6 ms |
1792 KB |
Output is correct |
10 |
Correct |
5 ms |
1792 KB |
Output is correct |
11 |
Correct |
6 ms |
1664 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
384 KB |
Output is correct |
2 |
Correct |
5 ms |
384 KB |
Output is correct |
3 |
Correct |
5 ms |
896 KB |
Output is correct |
4 |
Correct |
5 ms |
1792 KB |
Output is correct |
5 |
Correct |
6 ms |
1664 KB |
Output is correct |
6 |
Correct |
5 ms |
1792 KB |
Output is correct |
7 |
Correct |
5 ms |
1536 KB |
Output is correct |
8 |
Correct |
5 ms |
1664 KB |
Output is correct |
9 |
Correct |
6 ms |
1792 KB |
Output is correct |
10 |
Correct |
5 ms |
1792 KB |
Output is correct |
11 |
Correct |
6 ms |
1664 KB |
Output is correct |
12 |
Correct |
52 ms |
33788 KB |
Output is correct |
13 |
Correct |
44 ms |
29944 KB |
Output is correct |
14 |
Correct |
52 ms |
33784 KB |
Output is correct |
15 |
Correct |
53 ms |
34040 KB |
Output is correct |
16 |
Correct |
51 ms |
33656 KB |
Output is correct |
17 |
Correct |
52 ms |
34040 KB |
Output is correct |
18 |
Correct |
40 ms |
27128 KB |
Output is correct |
19 |
Correct |
51 ms |
33144 KB |
Output is correct |
20 |
Correct |
52 ms |
34040 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
384 KB |
Output is correct |
2 |
Correct |
5 ms |
384 KB |
Output is correct |
3 |
Correct |
5 ms |
896 KB |
Output is correct |
4 |
Correct |
5 ms |
1792 KB |
Output is correct |
5 |
Correct |
6 ms |
1664 KB |
Output is correct |
6 |
Correct |
5 ms |
1792 KB |
Output is correct |
7 |
Correct |
5 ms |
1536 KB |
Output is correct |
8 |
Correct |
5 ms |
1664 KB |
Output is correct |
9 |
Correct |
6 ms |
1792 KB |
Output is correct |
10 |
Correct |
5 ms |
1792 KB |
Output is correct |
11 |
Correct |
6 ms |
1664 KB |
Output is correct |
12 |
Correct |
52 ms |
33788 KB |
Output is correct |
13 |
Correct |
44 ms |
29944 KB |
Output is correct |
14 |
Correct |
52 ms |
33784 KB |
Output is correct |
15 |
Correct |
53 ms |
34040 KB |
Output is correct |
16 |
Correct |
51 ms |
33656 KB |
Output is correct |
17 |
Correct |
52 ms |
34040 KB |
Output is correct |
18 |
Correct |
40 ms |
27128 KB |
Output is correct |
19 |
Correct |
51 ms |
33144 KB |
Output is correct |
20 |
Correct |
52 ms |
34040 KB |
Output is correct |
21 |
Runtime error |
103 ms |
75000 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
22 |
Halted |
0 ms |
0 KB |
- |