////   This file contains the C++ code from Program 7.18 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/pgm07_18.cpp//class Term : public Object{    double coefficient;    unsigned int exponent;public:    Term (double, unsigned int);    // ...    int CompareTo (Object const&) const;    void Differentiate ();};Term::Term (double _coefficient, unsigned int _exponent) :    coefficient (_coefficient),    exponent (_exponent)    {}int Term::CompareTo (Object const& object) const{    Term const& term = dynamic_cast<Term const&> (object);    if (exponent == term.exponent)	return ::Compare (coefficient, term.coefficient);    else	return exponent - term.exponent;}void Term::Differentiate (){    if (exponent > 0)    {	coefficient *= exponent;	exponent -= 1;    }    else	coefficient = 0;}