/**
 * krq.c
 *   The K&R Quicksort.
 */

#include "sort.h"
#include "swap.h"

/**
 * kr_qsort: sort v[left]...v[right] into increasing alphabetical order.
 *   Note: Renamed to avoid conflict with qsort in stlib.h.
 */ 
void 
sort (char *v[], int size)
{
  int i, last;
  int left = 0;
  int right = size-1;

  /* If the array contains fewer than two elements, do nothing. */
  if (left >= right) 
    return;
  swap(v, left, (left + right)/2);
  last = left; 
  for (i = left+1; i <= right; i++) 
    if (strcmp (v[i], v[left]) < 0)
      swap(v, ++last, i); 

  swap(v, left, last);

  sort (v, last);
  sort (v+last+1, size-last-1);
} // qsort