ex13_28.h

//
//  ex13_28.h
//  Exercise 13.28
//
//  Created by pezy on 1/20/15.
//  Copyright (c) 2015 pezy. All rights reserved.
//
//  Given the following classes, implement a default constructor and the
//  necessary copy-control members.

#ifndef CP5_ex13_28_h
#define CP5_ex13_28_h

#include <string>
using std::string;

class TreeNode {
public:
    TreeNode()
        : value(string()), count(new int(1)), left(nullptr), right(nullptr)
    {
    }
    TreeNode(const TreeNode& rhs)
        : value(rhs.value), count(rhs.count), left(rhs.left), right(rhs.right)
    {
        ++*count;
    }
    TreeNode& operator=(const TreeNode& rhs);
    ~TreeNode()
    {
        if (--*count == 0) {
            if (left) {
                delete left;
                left = nullptr;
            }
            if (right) {
                delete right;
                right = nullptr;
            }
            delete count;
            count = nullptr;
        }
    }

private:
    std::string value;
    int* count;
    TreeNode* left;
    TreeNode* right;
};

class BinStrTree {
public:
    BinStrTree() : root(new TreeNode()) {}
    BinStrTree(const BinStrTree& bst) : root(new TreeNode(*bst.root)) {}
    BinStrTree& operator=(const BinStrTree& bst);
    ~BinStrTree() { delete root; }

private:
    TreeNode* root;
};

#endif