把二元查找树转变成排序的双向链表

//c/c++/*  1.把二元查找树转变成排序的双向链表  题目：  输入一棵二元查找树，将该二元查找树转换成一个排序的双向链表。  要求不能创建任何新的结点，只调整指针的指向。          10     / /    6  14  / / / /  4  8 12 16      转换成双向链表  4=6=8=10=12=14=16。  */    #include "stdafx.h"  #include <iostream>  using namespace std;      struct TreeNode  {      int m_nValue; // value of node      TreeNode *m_pLeft; // left child of node      TreeNode *m_pRight; // right child of node  };    typedef TreeNode DoubleList;  DoubleList * pHead;  DoubleList * pListIndex;    //生成查找树  void adjust(TreeNode * & pCurrent, int value)  {      //根节点的处理，生成根节点,为pCurrent赋值  <span style="color:#FF0000;">重点理解：注意为传址，修改了main内的pRoot</span>      if(NULL == pCurrent)      {      TreeNode *pEnd = new TreeNode();      pEnd ->m_pLeft =NULL;      pEnd ->m_pRight = NULL;      pEnd ->m_nValue = value;      pCurrent = pEnd;      }      //      else      {   //在左子树添加          if (value<pCurrent->m_nValue)          {                adjust(pCurrent->m_pLeft,value);          }          //在右子树添加          else if(value>pCurrent->m_nValue)          {              adjust(pCurrent->m_pRight,value);          }          else          {          cout<<" 重 复 的 节 点 "<<endl;          }            }    }    void addList(TreeNode *pCurrent);  //covert the tree to link  void covertTreeToLink(TreeNode *pCurrent)  {      //中序读出      if(pCurrent==NULL)      {      return;      }            //遍历左子树      if(NULL != pCurrent->m_pLeft)      {      covertTreeToLink(pCurrent->m_pLeft);      }            //将根节点加进链表      addList(pCurrent);            //遍历右子树      if(NULL != pCurrent->m_pRight)      {          covertTreeToLink(pCurrent->m_pRight);      }  }  //添加节点到链表  void addList(TreeNode *pCurrent)  {    if(NULL ==pListIndex)      pHead = pListIndex;  else  {  pCurrent->m_pLeft = pListIndex;  pListIndex ->m_pRight = pCurrent;  pListIndex = pCurrent;//指针后移  }  cout<<"Now "<<pCurrent->m_nValue<<endl;  }    int main()  {   TreeNode * pRoot = NULL;      pListIndex = NULL;//链表的移动指针      pHead = NULL;//链表的头指针      adjust(pRoot, 10);      adjust(pRoot, 4);      adjust(pRoot, 6);      adjust(pRoot, 8);      adjust(pRoot, 12);      adjust(pRoot, 14);      adjust(pRoot, 15);      adjust(pRoot, 16);      covertTreeToLink(pRoot);      getchar();      return 0;  }