Method1) Modified Quick sort
 
Stop processing when pivot is kth element
void q_select( int a[], const  unsigned int k, const unsigned int left,
const unsigned int right)
{
         if(left<=right)
         {
           int pivot=median3(a,left,right);
           unsigned int m=left, n=right-1;
           while(1)
           {
             while( a[++m]< pivot);
             while( a[++n]> pivot);
             if(i                swap(a[m],a[n]);
             else
               break;
           }
           swap(a[m], a[right-1]);
           if(k              q_select(a,k,left,m-1);
           else
             q_select(a,k,m+1,right);
         }
}
 
 

Method2)
 
Make a heap of k element
At the end of visiting all the element the head
will give the kth largest element
 
 

Method3)
 
Sort the element.
Get the value in the kth index