线索二叉树

来源：互联网发布：wind数据库多少钱编辑：程序博客网时间：2024/05/28 16:15

这里写图片描述

BinaryTreeThreading.h

#pragma once#include<iostream>using namespace std;enum PointerTag{    LINK, //指针，指向左右孩子    THREAD, //线索，指向前驱或后继};template<class T>struct BinTreThrNode{    BinTreThrNode(const T& x)    :_value(x)    , _leftChild(NULL)    , _rightChild(NULL)    , _LTag(LINK)    , _RTag(LINK)    {}    T _value;    BinTreThrNode<T>* _leftChild;    BinTreThrNode<T>* _rightChild;    PointerTag _LTag;    PointerTag _RTag;};template<class T>class BinaryTreeThread{public:    BinaryTreeThread(T* arr, size_t size)    {        int index = 0;        _CreateTree(_root,arr,size,index);    }    void InOrderThearding() //中序遍历线索化    {        BinTreThrNode<T>* prev = NULL;        _InOrderThearding(_root,prev);    }    void PrevOrderThearding() //前序遍历线索化    {        BinTreThrNode<T>* prev = NULL;        _PrevOrderThearding(_root, prev);    }    void PostOrderThearding() //后序遍历线索化    {        BinTreThrNode<T>* prev = NULL;        _PostOrderThearding(_root, prev);    }    void InOrder()    {        cout << "中序遍历：";        BinTreThrNode<T>* cur = _root;        while (cur)        {            while (cur && cur->_LTag != THREAD)            {                cur = cur->_leftChild;            }            cout << cur->_value << " ";            if (cur->_RTag != THREAD)            {                cur = cur->_rightChild;            }            else            {                cur = cur->_rightChild;                cout << cur->_value << " ";                while (cur->_RTag == THREAD) //防止死循环                {                    cur = cur->_rightChild;                    cout << cur->_value << " ";                }                cur = cur->_rightChild;            }        }        cout << endl;    }    void PrevOrder()    {        cout << "前序遍历：";        BinTreThrNode<T>* cur = _root;        while (cur)        {            while (cur->_LTag != THREAD)            {                cout << cur->_value<<" ";                cur = cur->_leftChild;            }            cout << cur->_value<<" ";            cur = cur->_rightChild;        }    }    void PostOrder()    {        cout << "后序遍历：";        BinTreThrNode<T>* cur = _root;        BinTreThrNode<T>* prev = _root;        while (cur)        {            while (cur->_LTag != THREAD && prev->_rightChild != cur)            {                cur = cur->_leftChild;            }            cout << cur->_value << " ";            if (cur->_RTag == THREAD)            {                prev = cur;            }            if (prev->_rightChild == cur && cur != _root) //防止死循环            {                cur = _root;            }            if (cur->_rightChild != prev)            {                cur = cur->_rightChild;            }            else            {                return;            }        }    }private:    void _CreateTree(BinTreThrNode<T>*& root, T* arr, size_t size,int& index) //index要用引用    {        if (arr[index] != '#' && index < size)            {                root = new BinTreThrNode<T>(arr[index]);                _CreateTree(root->_leftChild,arr,size,++index);                _CreateTree(root->_rightChild,arr,size,++index);            }    }    void _InOrderThearding(BinTreThrNode<T>*& root, BinTreThrNode<T>*& prev)    {        BinTreThrNode<T>* cur = root;        if (cur && cur->_leftChild)        {            _InOrderThearding(cur->_leftChild, prev);        }        if (cur->_leftChild == NULL)        {            cur->_leftChild = prev;            cur->_LTag = THREAD;        }        if (prev && prev->_rightChild == NULL)        {            prev->_rightChild = cur;            prev->_RTag = THREAD;        }        prev = cur;        if (cur && cur->_rightChild)        {            _InOrderThearding(cur->_rightChild, prev);        }    }    void _PrevOrderThearding(BinTreThrNode<T>*& root, BinTreThrNode<T>*& prev)    {        BinTreThrNode<T>* cur = root;        if (cur->_leftChild == NULL)        {            cur->_LTag = THREAD;            cur->_leftChild = prev;        }        if (prev && prev->_rightChild == NULL)        {            prev->_rightChild = cur;            prev->_RTag = THREAD;        }        prev = cur;        if (cur && cur->_LTag != THREAD)        {            _PrevOrderThearding(cur->_leftChild, prev);        }        if (cur->_rightChild && cur->_RTag != THREAD)        {            _PrevOrderThearding(cur->_rightChild, prev);        }    }    void _PostOrderThearding(BinTreThrNode<T>*& root, BinTreThrNode<T>*& prev)    {        BinTreThrNode<T>* cur = root;        if (cur)        {            _PostOrderThearding(cur->_leftChild, prev);            _PostOrderThearding(cur->_rightChild, prev);            if (cur->_leftChild == NULL)            {                cur->_LTag = THREAD;                cur->_leftChild = prev;            }            if (prev && prev->_rightChild == NULL && prev != cur)            {                prev->_rightChild = cur;                prev->_RTag = THREAD;            }            prev = cur;        }    }private:    BinTreThrNode<T>* _root;};

main.cpp

#include"BinaryTreeThreading.h"void Test(){    int arr[] = { 1, 2, 3, '#', '#', '#', 4, 5 };    BinaryTreeThread<int> bt(arr, 8);    //bt.InOrderThearding();    //bt.InOrder();    /*bt.PrevOrderThearding();    bt.PrevOrder();*/    bt.PostOrderThearding();    bt.PostOrder();}void Test1(){    int arr[] = { 1, 2, 3, '#', '#', 4,'#' ,'#', 5 ,6};    BinaryTreeThread<int> bt(arr, 10);    //bt.InOrderThearding();    //bt.InOrder();    /*bt.PrevOrderThearding();    bt.PrevOrder();*/    bt.PostOrderThearding();    bt.PostOrder();}int main(){    Test();    getchar();    return 0;}

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