最近想复习一下数据结构和算法,所以就写了一个二叉树的创建和遍历

// test2.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#include<iostream>
using namespace std;

struct tree//树结构体
{
 int data;
 tree *left,*right;
};
class Ctree
{

public:
 static int n;
 static int m;
 tree *root;
 Ctree()
 {
 root=NULL;

}
 void CreateTreeNode(int a);//创建树节点;
 int Sum(tree*);
 void PreOrder(tree*);
 void MedialOrder(tree*);
 void BackOrder(tree*);
};
int Ctree::m=0;
int Ctree::n=0;

void Ctree::CreateTreeNode(int data)
{
 tree *newNode=new tree;

 newNode->data=data;
 newNode->right=newNode->left=NULL;
 if(root==NULL)
 root=newNode;
 else
 {
 tree *tail;
 tree *cur=root;

 while(cur!=NULL)
 { tail=cur;

 if(data<cur->data)
 cur=cur->left;
 else
 cur=cur->right;
 }
 if(data<tail->data)
 tail->left=newNode;
 else
 tail->right=newNode;
 }

}

int Ctree::Sum(tree *p)//计算结点数
{
 if(p==NULL)
 return 0;
 else
 return Sum(p->left)+Sum(p->right)+1;
}

void Ctree::PreOrder(tree *p)//先序遍历;
{
 if(p!=NULL)
 {
 cout<<p->data<<endl;
 PreOrder(p->left);
 PreOrder(p->right);
 }
}
void Ctree::MedialOrder(tree*p)//中序遍历
{

if(p!=NULL)
 {
 MedialOrder(p->left);
 cout<<p->data<<endl;
 MedialOrder(p->right);
 }
}

void Ctree::BackOrder(tree *p)//后序遍历
{
 if(p!=NULL)
 {
 BackOrder(p->left);
 BackOrder(p->right);
 cout<<p->data<<endl;
 }
}
int main(int argc, char* argv[])
{
 Ctree *T=new Ctree();

T->CreateTreeNode(10);//根结点
 T->CreateTreeNode(7);
 T->CreateTreeNode(8);
 T->CreateTreeNode(11);
 T->CreateTreeNode(9);
 T->CreateTreeNode(6);

cout<<"结点数:"<<T->Sum(T->root)<<endl;
 cout<<"先序遍历:"<<endl;
 T->PreOrder(T->root);
 cout<<"中序遍历:"<<endl;
 T->MedialOrder(T->root);
 cout<<"后序遍历:"<<endl;
 T->BackOrder(T->root);
 getchar();
 return 0;
}

&nbsp;

输出结果如下: