////   This file contains the C++ code from Program 14.7 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/pgm14_07.cpp//void BreadthFirstSolver::DoSolve (Solution const& initial){    Queue& queue = *new QueueAsLinkedList ();    queue.Enqueue (initial.Clone ());    while (!queue.IsEmpty ())    {	Solution& solution =	    dynamic_cast<Solution&> (queue.Dequeue ());	if (solution.IsComplete ())	    UpdateBest (solution);	else	{	    Iterator& i = solution.Successors ();	    while (!i.IsDone ()) {		Solution& succ = dynamic_cast<Solution&> (*i);		queue.Enqueue (succ);		++i;	    }	    delete &i;	}	delete &solution;    }    delete &queue;}