csu-1212 快排

#include<stdio.h>
#include<stdlib.h>
#define MAXN 200000 + 10
int sort[MAXN];
int compare (const void * a, const void * b)
{
return ( *(int*)a - *(int*)b );
}
int main()
{
int n, i, k ;
//freopen("in.txt","r",stdin);
//freopen("out.txt","w",stdout);
while(scanf("%d",&n) == 1)
{
for(i = 1; i <= 2*n; i++)
{
scanf("%d",&k);
sort[i-1] = k;
}
qsort (sort, 2*n, sizeof(int), compare);
printf("%d\n",sort[(2*n-1)/2]);
}

return 0;
}