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Submission #491770

# Submission time Handle Problem Language Result Execution time Memory
491770 2021-12-04T10:07:32 Z shahriarkhan Kangaroo (CEOI16_kangaroo) C++14
100 / 100
 27 ms 22988 KB 
#include<bits/stdc++.h>
using namespace std ;

const long long mod = 1e9 + 7 , mx = 2005 ;

long long dp[mx][mx] ;

int main()
{
    int n , cs , cf ;
    scanf("%d%d%d",&n,&cs,&cf) ;
    dp[1][1] = 1 ;
    int in = ((1==cf) || (1==cs)) ;
    for(int i = 1 ; i < n ; ++i)
    {
        if(((i+1)==cf) || ((i+1)==cs)) ++in ;
        for(int j = 1 ; j <= i ; ++j)
        {
            if(((i+1)==cs) || ((i+1)==cf))
            {
                dp[i+1][j+1] = (dp[i+1][j+1] + dp[i][j])%mod ;
                dp[i+1][j] = (dp[i+1][j] + dp[i][j])%mod ;
            }
            else
            {
                dp[i+1][j+1] = (dp[i+1][j+1] + ((dp[i][j]*(j+1-in))%mod))%mod ;
                dp[i+1][j-1] = (dp[i+1][j-1] + ((dp[i][j]*(j-1))%mod))%mod ;
            }
        }
    }
    printf("%lld\n",dp[n][1]) ;
    return 0 ;
}

Compilation message

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:11:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |     scanf("%d%d%d",&n,&cs,&cf) ;
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 332 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 1 ms 436 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 0 ms 460 KB Output is correct
9 Correct 0 ms 460 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 460 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 1 ms 436 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 0 ms 460 KB Output is correct
9 Correct 0 ms 460 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 460 KB Output is correct
12 Correct 2 ms 1228 KB Output is correct
13 Correct 1 ms 1100 KB Output is correct
14 Correct 1 ms 1228 KB Output is correct
15 Correct 1 ms 1228 KB Output is correct
16 Correct 1 ms 1228 KB Output is correct
17 Correct 1 ms 1228 KB Output is correct
18 Correct 1 ms 1100 KB Output is correct
19 Correct 1 ms 1228 KB Output is correct
20 Correct 1 ms 1228 KB Output is correct

Subtask #4
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 1 ms 436 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 0 ms 460 KB Output is correct
9 Correct 0 ms 460 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 460 KB Output is correct
12 Correct 2 ms 1228 KB Output is correct
13 Correct 1 ms 1100 KB Output is correct
14 Correct 1 ms 1228 KB Output is correct
15 Correct 1 ms 1228 KB Output is correct
16 Correct 1 ms 1228 KB Output is correct
17 Correct 1 ms 1228 KB Output is correct
18 Correct 1 ms 1100 KB Output is correct
19 Correct 1 ms 1228 KB Output is correct
20 Correct 1 ms 1228 KB Output is correct
21 Correct 4 ms 4556 KB Output is correct
22 Correct 4 ms 4940 KB Output is correct
23 Correct 5 ms 5580 KB Output is correct
24 Correct 24 ms 22900 KB Output is correct
25 Correct 26 ms 22928 KB Output is correct
26 Correct 27 ms 22988 KB Output is correct
27 Correct 25 ms 22724 KB Output is correct
28 Correct 21 ms 15036 KB Output is correct