Quicksort algorithm

This is the fastest non-destructive sort known and given how sorts must work, this is likely to be the fastest sort ever.

// sort everything inbetween `low' and `high'
void quicksort(int arr[], int low, int high)
{
   int i = low;
   int j = high;
   int y = 0;

   int z = arr[(low + high) / 2];// comparison value

   do // partition
   {
       while(arr[i] < z) i++; // find high element ... 
       while(arr[j] > z) j--; // find low element ... 

       if(i <= j) // swap two elements 
       {
           y = arr[i];
           arr[i] = arr[j];
           arr[j] = y;
           i++;
           j--;
       }
   } while(i <= j);

   // recurse to smaller subsets until everything is sorted
   if(low < j)
   { quicksort(arr, low, j); }

   if(i > high)
   { quicksort(arr, i, high); }
}