二叉树的基本操作

唯一需要注意的就是里面几种遍历的非递归实现，借助了队列和栈来进行实现。
下面是完整的代码：

#pragma once#include<iostream>#include<stack>#include<queue>using namespace std;//孩子表示法template<class T>struct BinaryTreeNode{    BinaryTreeNode(const T& value)    :_value(value)    , _pLeft(NULL)    , _pRight(NULL)    {};    T _value;    BinaryTreeNode<T>* _pLeft;    BinaryTreeNode<T>* _pRight;};template<class T>class BinaryTree{    typedef BinaryTreeNode<T> Node;public:    BinaryTree()        :_pRoot(NULL)    {}    BinaryTree(const T array[], size_t size, const T& invalid)    {        size_t index = 0;//        _CreateBinaryTree(_pRoot, array, size, index, invalid);    }    //下面使用到了&index,但是不能对一个常量进行引用，所以要把index定义为一个变量    BinaryTree(const BinaryTree<T>& bt)    {        _pRoot = CopyBinaryTree(bt._pRoot);    }    BinaryTree<T>& operator=(const BinaryTree<T>& bt)    {        if (this != &bt)        {            _DestroyBinaryTree(_pRoot);            _pRoot = CopyBirnaryTree(bt._pRoot);        }        return *this;    }    ~BinaryTree()    {        _DestroyBinaryTree(_pRoot);    }    void PreOrder()    {        cout << "PreOrder:" << endl;        _PreOrder(_pRoot);        cout << endl;    }    void PostOrder()    {        cout << "PostOrder:" << endl;        _PostOrder(_pRoot);        cout << endl;    }    void MidOrder()    {        cout << "MidOrder:" << endl;        _MidOrder(_pRoot);        cout << endl;    }    Node* Find(const T& value)    {        return _Find()    }    void PostOrder_Nor()//非递归实现后序    {        cout << "PostOrder_Nor:" << endl;        if (NULL == _pRoot)            return;        stack<Node*> s;        Node* pCur = _pRoot;        Node* pPre = NULL;        while (pCur || !s.empty())        {            while (pCur)            {                s.push(pCur);                pCur = pCur->_pLeft;            }            Node* pTop = s.top();            if (NULL == pTop->_pRight || pTop->_pRight == pPre)            {                cout << pTop->_value << " ";                pPre = pTop;                s.pop();            }            else                pCur = pTop->_pRight;        }    }    void MidOrder_Nor()//非递归实现中序    {        cout << "MidOrder_Nor:" << endl;        if (NULL == _pRoot)            return;        stack<Node*> s;        Node *pCur = _pRoot;        while (!s.empty() || pCur)        {            while (pCur)            {                s.push(pCur);                pCur = pCur->_pLeft;            }            if (NULL == pCur && !s.empty())            {                pCur = s.top();                cout << pCur->_value << " ";                s.pop();                pCur = pCur->_pRight;            }        }    }    void PreOrder_Nor()//非递归实现前序    {        if (NULL == _pRoot)            return;        stack<Node*> s;        s.push(_pRoot);        while (!s.empty())        {            Node* pTop = s.top();            cout << pTop->_value << " ";            s.pop();            if (pTop->_pRight)                s.push(pTop->_pRight);            if (pTop->_pLeft)                s.push(pTop->_pLeft);        }    }    bool IsComPleteBinaryTree()//利用层序遍历判断是否为完全二叉树    {        if (NULL == _pRoot)            return true;        bool flag = false;        queue<Node*> q;        Node* pCur = _pRoot;        q.push(_pRoot);        while (!q.empty())        {            Node* pCur = q.front();            if (flag)            {                if (pCur->_pLeft || pCur->_pRight)                    return false;            }            else            {                if (pCur->_pLeft&&pCur->_pRight)                {                    q.push(pCur->_pLeft);                    q.push(pCur->_pRight);                }                else if (pCur->_pLeft)                {                    q.push(pCur->_pLeft);                    flag = true;                }                else if (pCur->_pRight)                {                    q.push(pCur->_pRight);                    flag = false;                }                else                    flag = true;            }            q.pop();        }        return true;    }private:    void _CreateBinaryTree(Node* &pRoot, const T array[],size_t size, size_t& index,const T& invalid)    {        if (index < size && invalid != array[index])//注意条件的判断次序        {            //创建根节点            pRoot = new Node(array[index]);            //创建左子数            _CreateBinaryTree(pRoot->_pLeft, array, size, ++index,invalid);//如果用index+1，初始的index并没有发生变化            //创建右子数            _CreateBinaryTree(pRoot->_pRight, array, size, ++index, invalid);        }    }    Node* CopyBirnaryTree(Node* pRoot)    {        Node* pNewNode = NULL;        //拷贝根节点        if (pRoot)        {            pNewNode = new Node(pRoot->_value);            //拷贝左子树            pNewNode->_pLeft = CopyBirnaryTree(pRoot->_pLeft);            //拷贝右子树             pNewNode->_pRight = CopyBirnaryTree(pRoot->_pRight);        }        return pNewNode;    }    void _DestroyBinaryTree(Node* &pRoot)    {        if (pRoot)        {            _DestroyBinaryTree(pRoot->_pLeft);            _DestroyBinaryTree(pRoot->_pRight);            delete pRoot;            pRoot = NULL;        }    }    void _PreOrder(Node* pRoot)    {        if (pRoot)        {            cout << pRoot->_value << " ";            _PreOrder(pRoot->_pLeft);            _PreOrder(pRoot->_pRight);        }    }    void _PostOrder(Node* pRoot)    {        if (pRoot)        {            _PreOrder(pRoot->_pLeft);                   _PreOrder(pRoot->_pRight);            cout << _pRoot->_value << " ";        }    }    void _MidOrder(Node* pRoot)    {        if (pRoot)        {            _PreOrder(pRoot->_pLeft);            cout << _pRoot->_value << " ";            _PreOrder(pRoot->_pRight);        }    }private:    Node* _pRoot;//根节点};int main(){    char* ptr = "124###35##6";    BinaryTree<char> bt(ptr, strlen(ptr), '#');    //BinaryTree<char> bt1(bt);    //bt.PostOrder();    bt.MidOrder_Nor();    /*bt.MidOrder();    BinaryTree<char> bt2;    bt2 = bt;    bt2.PreOrder();    bt2.PostOrder_Nor();    bt2.IsComPleteBinaryTree();*/    return 0;}