////   This file contains the C++ code from Program 11.20 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/pgm11_20.cpp//Object& BinomialQueue::DequeueMin (){    if (count == 0)	throw domain_error ("priority queue is empty");    BinomialTree& minTree = FindMinTree ();    RemoveTree (minTree);    BinomialQueue queue;    while (minTree.Degree () > 0)    {	BinomialTree& child = minTree.Subtree (0);	minTree.DetachSubtree (child);	queue.AddTree (child);    }    Merge (queue);    Object& result = minTree.Key ();    minTree.RescindOwnership ();    delete &minTree;    return result;}