Squares

#include<stdio.h>
#include<math.h>
int a[51];
int swap(int n,int m)
{
    int t;
    t=a[n];
    a[n]=a[m];
    a[m]=t;
    return 0;
}
int qs(int l,int r)
{
    int i,j,x;
    if (l<r)
    {
        i=l;
        j=r;
        x=a[i];
        while(i<j)
        {
            while(i<j&&a[j]>x)j--;
            if(i<j)a[i++]=a[j];
            while(i<j&&a[i]<x)i++;
            if(i<j)a[j--]=a[i];
        }
        a[i]=x;
        qs(l,i-1);
        qs(i+1,r);
    }
}

int main()
{
    int n,k,m,i,j;
    scanf("%d %d",&n,&k);
    for(i=1;i<=n;i++)
        scanf("%d",&a[i]);
    if(n-k+1<=0||n-k+1>n)printf("-1");
    else
    {
        qs(1,n);
        printf("%d 0",a[n-k+1]);
    }
    return 0;
} 

http://codeforces.com/contest/263/problem/B