Submission #771715

#	Time	Username	Problem	Language	Result	Execution time	Memory
771715		Amylopectin	Kangaroo (CEOI16_kangaroo)	C++14	100 / 100	20 ms	24004 KiB

kangaroo

#include <stdio.h>
#include <iostream>

using namespace std;
const long long mxn = 3e3 + 10,mo = 1e9 + 7;
long long dp[mxn][mxn] = {};
int main()
{
    long long i,j,n,m,stt,enn,cap,cou = 0;
    scanf("%lld %lld %lld",&n,&stt,&enn);
    dp[0][0] = 1;
    cap = n/2 + 2;
    for(i=1; i<=n; i++)
    {
        if(i == stt || i == enn)
        {
            cou ++;
            for(j=0; j<=cap; j++)
            {
                dp[i][j+1] += dp[i-1][j];
                dp[i][j+1] %= mo;
                dp[i][j] += dp[i-1][j];
                dp[i][j] %= mo;
            }
            continue;
        }
        for(j=0; j<=cap; j++)
        {
            // if(j > 0)
                dp[i][j] += dp[i-1][j+1] * (j);
                dp[i][j] %= mo;
            if(j+1-cou >= 0)
                dp[i][j+1] += dp[i-1][j] * (j+1-cou);
            dp[i][j+1] %= mo;
        }
    }
    printf("%lld\n",dp[n][1]);
    return 0;
}

Compilation message (stderr)

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:9:21: warning: unused variable 'm' [-Wunused-variable]
    9 |     long long i,j,n,m,stt,enn,cap,cou = 0;
      |                     ^
kangaroo.cpp:10:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |     scanf("%lld %lld %lld",&n,&stt,&enn);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 30 / 30
• Subtask 3: 15 / 15
• Subtask 4: 49 / 49