C++创建二叉树（一）

来源：互联网发布：toefl培训知乎编辑：程序博客网时间：2024/05/22 17:31

本文实现的二叉树功能包含：

//  拷贝构造函数//  重载 operator=//  创建二叉树（5种创建方法）//  递归遍历  （先序，中序，后序） //  //接下来的文章将实现：非递归遍历二叉树，创建二叉树（先中序，中后序）//              二叉树的结点个数，深度，查找结点，查找双亲等

附一张二叉树结构图
这里写图片描述

二叉树模板类的定义

//只给出了public方法template<class Type>class BinaryTree{protected:    typedef struct BtNode//二叉树结点    {        Type data;        BtNode* leftchild;        BtNode* rightchild;    };public:    BinaryTree();    BinaryTree(const Type &x);        BinaryTree(const BinaryTree &tree);     //拷贝构造函数    BinaryTree & operator=(BinaryTree &obj);//重载operator方法    ~BinaryTree();public:    void MakeTree(const Type *&str);//内部包含5种创建方法    void PreOrder() const;          //先序遍历（递归）    void InOrder()  const;          //中序遍历 (递归)    void PastOrder()const;          //后序遍历 (递归)private:    BtNode* root;    Type    RefValue;//叶子结点标志};

代码实现

#include<iostream>#include<assert.h>#include<stdlib.h>using namespace std;template<class Type>class BinaryTree{protected:    typedef struct BtNode    {        Type data;        BtNode* leftchild;        BtNode* rightchild;    };    typedef BtNode* PBtree;public:    BinaryTree():root(NULL),RefValue(NULL){}    BinaryTree(const Type &x):root(NULL),RefValue(x){}    BinaryTree(const BinaryTree &tree)    {        root = Copy(tree.root);    }    BinaryTree & operator=(BinaryTree &obj)    {        if(this != &obj)        {            root = Copy(obj.root);        }        return *this;    }    ~BinaryTree(){}public:    void MakeTree(const Type *&str)    {        if(NULL == str)        {            root = NULL;        }        else        {//5种创建二叉树的方法：中间三种方法终端输入            root = Create(str);            //Create1(root);            //root = Create2();            //Create3(&root);            //root = Create4(&str);        }    }    void PreOrder()const    {        cout <<endl<< "先序遍历(递归)  : ";        PreOrder(root);        cout << endl;    }    void InOrder()const    {        cout  << "中序遍历(递归)  : ";        InOrder(root);        cout << endl;    }    void PastOrder()const    {        cout  << "后序遍历(递归)  : ";        PastOrder(root);        cout << endl;    }private:    static BtNode* Buynode()    {        BtNode *s = (BtNode*)malloc(sizeof(BtNode));        assert(s != NULL);        memset(s,0,sizeof(BtNode));        return s;    }    static void Freenode(BtNode *p)    {        free(p);    }    BtNode *Create(const Type *&str)    {        if(*str == RefValue)return NULL;        else        {            BtNode *s = Buynode();            s->data = *str;            s->leftchild = Create(++str);            s->rightchild = Create(++str);            return s;        }    }    void Create1(BtNode *&p)    {        Type x;        cin>>x;        if(x == RefValue) p = NULL;        else        {            p = Buynode();            p->data = x;            Create1(p->leftchild);            Create1(p->rightchild);        }    }    BtNode *Create2()    {        Type x;        BtNode *s=NULL;        cin>>x;        if(x != RefValue)        {            s = Buynode();            s->data = x;            s->leftchild = Create2();            s->rightchild= Create2();        }        return s;    }    void Create3(BtNode **p)    {        Type x;        cin>>x;        if(x == RefValue) p=NULL;        else        {            *p= Buynode();            (*p)->data = x;            //Create3(&(*p)->leftchild); //两种写法都可以            Create3(&(**p).leftchild);            Create3(&(**p).rightchild);        }    }    BtNode *Create4(const Type **str)    {        BtNode *s = NULL;        if(**str != RefValue)        {            s = Buynode();            s->data = **str;            s->leftchild = Create4(&++*str);            s->rightchild= Create4(&++*str);        }        return s;    }    static void PreOrder(BtNode *p)    {        if(NULL != p)        {            cout<<p->data<<"  ";            PreOrder(p->leftchild);            PreOrder(p->rightchild);        }    }    static void InOrder(BtNode *p)    {        if(NULL != p)        {            InOrder(p->leftchild);            cout<<p->data<<"  ";            InOrder(p->rightchild);        }       }    static void PastOrder(BtNode *p)    {        if(NULL != p)        {            PastOrder(p->leftchild);            PastOrder(p->rightchild);            cout<<p->data<<"  ";        }    }    static BtNode *Copy(const BtNode *p)    {        BtNode *newroot;        if(NULL == p)return NULL;        else        {            newroot = Buynode();            newroot->data = p->data;            newroot->leftchild  = Copy(p->leftchild);            newroot->rightchild = Copy(p->rightchild);            return newroot;        }    }private:    BtNode* root;    Type    RefValue;};int main(){    BinaryTree<char> mytree('#');    char *str="ABC##DE##F##G#H##";    mytree.MakeTree(str);    mytree.PreOrder();    mytree.InOrder();    mytree.PastOrder();    BinaryTree<char> youtree(mytree);//拷贝构造    youtree.PreOrder();    youtree.InOrder();    youtree.PastOrder();    BinaryTree<char> histree;    histree=mytree;                  //赋值语句（重载operator=方法）    histree.PreOrder();    histree.InOrder();    histree.PastOrder();    return 0;}

1 0