<?php

/********************************************************
* 我写的PHP都是从C语言的数据结构中演化而来************************
**************************************************************
/**
 *    ******二叉树图****
      *      A                    * 
      *     * *                   * 
      *    *   *                  * 
      *   B     C                *       
      *        *                   * 
      *       *                    *
      *      D                    *  
      *       *                    *
      *         *E                *
      ******************

 * PHP- 链式二叉树的遍历---先序遍历（根,左,右）-中序遍历(左,根,右)-后序遍历(左,右，根)
 * 先 A B C D E
 * 中 B A D E C
 * 后 B E D C A
 * @Author 任孟洋 
 * @time   2013-8-10
 ****/
 

 Class  BTreeNode{
      
         public  $data ; //数据域
         public  $LeftHand  = NULL ; //左指针
         public  $RightHand = NULL ; //右指针

          public function  __construct($data){
        
                if(!empty($data))
                {

                    $this->data = $data;
                }
          }
          
          
          //先序遍历（根，左，右）递归实现
          public  function PreTraverseBTree($BTree){

                 if (NULL !== $BTree)
                 {               
                   var_dump($BTree->data);  //根

                   if (NULL !== $BTree->LeftHand)
                    {
                       $this->PreTraverseBTree($BTree->LeftHand); //递归遍历左树
                    }
           
                    
                   if (NULL !== $BTree->RightHand)
                    {
                       $this->PreTraverseBTree($BTree->RightHand); //递归遍历右树
                    }
                   
                 } 
            }

           //中序遍历(左，根，右)递归实现
           public  function  InTraverseBTree($BTree){
                 
                 if (NULL !== $BTree)
                 {              
                   if (NULL !== $BTree->LeftHand)
                    {
                       $this->InTraverseBTree($BTree->LeftHand); //递归遍历左树
                    }
           
                    var_dump($BTree->data); //根 

                   if (NULL !== $BTree->RightHand)
                    {
                       $this->InTraverseBTree($BTree->RightHand); //递归遍历右树
                    }
                   
                 } 
                 
           }

           //后序遍历(左，右，根)递归实现
          public  function  FexTarverseBTree($BTree){
               
                if (NULL !== $BTree)
                 {
                   if (NULL !== $BTree->LeftHand)
                    {
                       $this->FexTarverseBTree($BTree->LeftHand); //递归遍历左树
                    }
           
                    
                   if (NULL !== $BTree->RightHand)
                    {
                       $this->FexTarverseBTree($BTree->RightHand); //递归遍历右树
                    }
                    var_dump($BTree->data); //根
                 } 
           } 
}
 
 header("Content-Type:text/html;charset=utf-8");
 echo '先的内存为'.var_dump(memory_get_usage());
 echo '<hr/>';
 
   //创建五个节点
   $A  = new  BTreeNode('A');
   $B  = new  BTreeNode('B');
   $C  = new  BTreeNode('C');
   $D  = new  BTreeNode('D');
   $E  = new  BTreeNode('E');
   

   //连接形成一个二叉树

   $A->LeftHand  = $B;
   $A->RightHand = $C;
   $C->LeftHand  = $D;
   $D->RightHand = $E;
   
   //先序遍历
   echo '先序遍历的结果'.'<br>';
   $A->PreTraverseBTree($A);

   echo '<br/>中序遍历的结果'.'<br>';
   $A->InTraverseBTree($A);

   echo  '<br/>后序列遍历的结果'.'<br/>';
   $A->FexTarverseBTree($A);

   echo '<hr/>';
   echo '后的内存为'.var_dump(memory_get_usage());