////   This file contains the C++ code from Program 12.19 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/pgm12_19.cpp//Set& PartitionAsForest::Find (Object const& object) const{    unsigned int const item =	dynamic_cast<Set::Element const&> (object);    PartitionTree* ptr = array [item];    while (ptr->parent != 0)	ptr = ptr->parent;    return *ptr;}