微软100题（1） 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 <iostream>    #include <string>    using namespace std;       struct BSTreeNode{int m_nValue; // value of nodeBSTreeNode *m_pLeft; // left child of nodeBSTreeNode *m_pRight; // right child of node};typedef struct BSTreeNode DoubleList;;DoubleList * pHead;DoubleList * pListIndex;void ConvertToDoubleList(BSTreeNode *pCurrent);void AddBSTree(BSTreeNode *&pCurrent,int value){if(pCurrent == NULL){BSTreeNode * pBSNode = new BSTreeNode();pBSNode->m_pLeft = NULL;pBSNode->m_pRight = NULL;pBSNode->m_nValue = value;pCurrent = pBSNode;}else{if(pCurrent->m_nValue > value)AddBSTree(pCurrent->m_pLeft,value);else if (pCurrent->m_nValue < value)    AddBSTree(pCurrent->m_pRight,value);}}void InoderTraverse(BSTreeNode *pCurrent){if (pCurrent == NULL)   return ;if(pCurrent->m_pLeft != NULL)   InoderTraverse(pCurrent->m_pLeft);//二叉树——链表转换ConvertToDoubleList(pCurrent);if(pCurrent->m_pRight != NULL)   InoderTraverse(pCurrent->m_pRight);}void ConvertToDoubleList(BSTreeNode *pCurrent){pCurrent->m_pLeft = pListIndex;if(pListIndex == NULL){pHead = pCurrent;}else{pListIndex->m_pRight = pCurrent;}pListIndex = pCurrent;cout<<pCurrent->m_nValue<<" ";}