二元查找树转变成排序的双向链表（树）

/*
Name: 二元查找树转变成排序的双向链表（树）
Copyright:
Author: yifi
Date: 23/11/16 17:06
Description:
*/

#include <iostream>
using namespace std;

typedef struct _BSTreeNode{
int m_Value;
_BSTreeNode* pLeft;
_BSTreeNode* pRight;
}BSTreeNode,*pBSTreeNode;

void addBSTreeNode(BSTreeNode *&pCurrent,int value);
void inOrderBSTree(BSTreeNode* pBSTree);
void convertToDoubleList(BSTreeNode* pCurrent);

BSTreeNode *pHead=NULL;//指向循环队列头结点
BSTreeNode *pIndex=NULL;//指向前一个结点
int main()
{
BSTreeNode *pRoot=NULL;
addBSTreeNode(pRoot,10);
addBSTreeNode(pRoot,6);
addBSTreeNode(pRoot,14);
addBSTreeNode(pRoot,4);
addBSTreeNode(pRoot,8);
addBSTreeNode(pRoot,12);
addBSTreeNode(pRoot,16);
inOrderBSTree(pRoot);
return 0;
}

void addBSTreeNode(BSTreeNode *&pCurrent,int value)
{
if (pCurrent == NULL)
{
BSTreeNode* pTemp = new BSTreeNode();
pTemp->m_Value = value;
pTemp->pLeft = NULL;
pTemp->pRight = NULL;
pCurrent = pTemp;
}
else if (pCurrent->m_Value < value)
{
addBSTreeNode(pCurrent->pRight,value);
}
else if (pCurrent->m_Value > value)
{
addBSTreeNode(pCurrent->pLeft,value);
}
else
{
cout << "Node Repeated" << endl;
}
}

void inOrderBSTree(BSTreeNode* pBSTree)
{
if (pBSTree == NULL)
{
return ;
}
if (pBSTree->pLeft != NULL)
{
inOrderBSTree(pBSTree->pLeft);
}
convertToDoubleList(pBSTree);
if (pBSTree->pRight != NULL)
{
inOrderBSTree(pBSTree->pRight);
}

}
void convertToDoubleList(BSTreeNode* pCurrent)
{
pCurrent->pLeft = pIndex;
if (pIndex == NULL)
{
pHead = pCurrent;
}
else
{
pIndex->pRight = pCurrent;
}
pIndex = pCurrent;

cout << pCurrent->m_Value << " ";
}