#ifndef __SORT_H__
#define __SORT_H__

/**
 * Procedure:
 *   sort
 * Parameters:
 *   arr, an array of pointers.
 *   left, an integer.
 *   right, an integer
 *   comp, a comparator
 * Purpose:
 *   Sort arr[left..right] into increasing order.
 * Produces:
 *   [Nothing; Called for the side effect]
 * Preconditions:
 *   0 <= left <= right < length of arr.
 *   comp can be applied to all elements of the arrays.
 * Postconditions:
 *   Elements have neither been added nor removed, just rearranged.
 *   comp(arr[i],arr[i+1]) <= 0 for left <= i < right.
 */
void sort(void *arr[], int left, int right, 
          int (*comp)(const void *, const void *));

#endif // __SORT_H__