/**
 * reorder.h 
 *   A declaration of a variant of the infamous partition function 
 *   from Quicksort.
 */

#ifndef __REORDER_H__
#define __REORDER_H__

/**
 * Procedure:
 *   reorder
 * Parameters:
 *   a, an array
 *   size, an integer
 *   splitter, an integer
 * Purpose:
 *   Rearrange a so that all the values less than or equal to splitter
 *   fall at the left side of the array and all of the values greater than
 *   splitter fall at the right side of the array.
 * Produces:
 *   border, an integer
 * Preconditions:
 *   0 < size <= length of a
 * Postconditions:
 *   Values have neither been added to no removed from a.  (That is,
 *     the resulting array is a permutation of the original array.)
 *   There are border values in a that are <= splitter.
 *   0 <= border <= size.
 *   For 0 <= i < border, a[i] <= splitter.
 *   For border <= i <= size, a[i] > splitter.
 */
int reorder (int a[], int size, int splitter);

#endif // __REORDER_H__