pgm09_14.cpp

此文件为网络书籍数据结构的面向对象方法的源码

//
//   This file contains the C++ code from Program 9.14 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/pgm09_14.cpp
//
bool NaryTree::IsEmpty () const
    { return key == 0; }

Object& NaryTree::Key () const
{
    if (IsEmpty ())
	throw domain_error ("invalid operation");
    return *key;
}

void NaryTree::AttachKey (Object& object)
{
    if (!IsEmpty ())
	throw domain_error ("invalid operation");
    key = &object;
    subtree.SetLength (degree);
    for (unsigned int i = 0; i < degree; ++i)
	subtree [i] = new NaryTree (degree);
}

Object& NaryTree::DetachKey ()
{
    if (!IsLeaf ())
	throw domain_error ("invalid operation");
    Object& result = *key;
    key = 0;
    for (unsigned int i = 0; i < degree; ++i)
	delete subtree [i];
    subtree.SetLength (0);
    return result;
}