大家都知道二叉树最大的特点即只有两个节点，因此可以大致构建这一个二叉树类： 

#ifndef TREE_H
#define TREE_H
class Tree
{
public：
    int data;   //value值
    Tree *pleft;//左节点
    Tree *pright;//右结点

    Tree *pfather//父节点
    Tree(int da=0);构造函数
    void deleteNode();//删除一个节点函数
    Tree *searchNode(int index);//查找一个节点函数
    void priorTraverse();//先序遍历
    void midiaTraverse();//中序遍历
    void afterTraverse();//后序遍历
};

#endif

接下来就可以写对应的实现函数了：

1）首先是构造函数

Tree::Tree(int da) {
    data = da;
    pleft = NULL;
    pright = NULL;

    pfather=NULL;
}

2）节点删除函数

void Tree::deleteNode() {
    if (this->pleft != NULL)
    {
        this->pleft->deleteNode();
    }
    if (this->pright != NULL) {
        this->pright->deleteNode();
    }

    if (this->pfather != NULL) {
        if (this->pfather->pleft == this)
            this->pfather->pleft = NULL;
        if (this->pfather->pright == this)
            this->pfather->pright= NULL;
    }
    delete this;
}

3）节点查找函数

Tree *Tree::searchNode(int val) {
    if (this->data== index) {
        return this;
    }
   Tree *temp = NULL;
    if (pleft != NULL) {
        if (this->pleft->data== val)
            return this->pleft;
        else
        {
            temp = this->pleft->searchNode(val);
            if (temp != NULL)
                return temp;
        }
    }
    if (pright != NULL) {
        if (this->pright->data== val)
            return this->pright;
        else
            temp=this->pright->searchNode(val);
        return temp;
    }
    return NULL;
}

4)先序遍历

void Tree::priorTraverse() {
    cout << data << endl;
    if (this->pleft != NULL) {
        this->pleft->priorTraverse();
    }
    if (this->pright != NULL) {
        this->pright->priorTraverse();
    }
}

5）中序遍历
void Tree::midiaTraverse() {
    if (this->pleft != NULL) {
        this->pleft->midiaTraverse();
    }
    cout << data << endl;
    if (this->pright != NULL) {
        this->pright->midiaTraverse();
    }
}

6）后序遍历
void Tree::afterTraverse() {
    if (this->pleft != NULL) {
        this->pleft->afterTraverse();
    }
    if (this->pright != NULL) {
        this->pright->afterTraverse();
    }
    cout<< data << endl;
}

这样大致一颗二叉树类就建立好了

测试：

#include<iostream>
#include”tree.h”
using namespace std;
int main()
{
    Tree *root = new Tree(1);
    root->pleft = new Tree(2);
    root->pright = new Tree(3);
    root->pleft->pfather = root;
    root->pright->pfather = root;
    root->pleft->pleft = new Tree(4);
    root->pleft->pright = new Tree(5);
    root->pleft->pleft->pfather = root->pleft;
    root->pleft->pright->pfather = root->pleft;
    root->pright->pleft = new Tree(6);
    root->pright->pright = new Tree(7);
    root->pright->pleft->pfather = root->pright;
    root->pright->pright->pfather = root->pright;
    root->priorTraverse();
    cout << endl;
    root->midiaTraverse();
    cout << endl;
    root->afterTraverse();
    cout << endl;
    Tree *node = root->searchNode(3);
    cout << node->data << endl;
    node->deleteNode();
    root->priorTraverse();
    cout << endl;
}