////   This file contains the C++ code from Program 15.13 of//   "Data Structures and Algorithms//    with Object-Oriented Design Patterns in C++"//   by Bruno R. Preiss.////   Copyright (c) 1998 by Bruno R. Preiss, P.Eng.  All rights reserved.////   http://www.pads.uwaterloo.ca/Bruno.Preiss/books/opus4/programs/pgm15_13.cpp//template <class T>void HeapSorter<T>::PercolateDown (    Array<T>& array, unsigned int length, unsigned int i){    while (i <= length / 2)    {	unsigned int child = 2 * i;	if (child + 1 <= length		&& array [child + 1] > array [child])	    child = child + 1;	if (array [i] >= array [child])	    break;	Swap (array [i], array [child]);	i = child;    }}