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

/**copyright@nciaebupt 转载请注明出处*问题：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。*4=6=8=10=12=14=16*/#include <cstdio>#include <cstdlib>#include <iostream>#include <string>using namespace std;struct BSTreeNode{    int value;    BSTreeNode * left;    BSTreeNode * right;};BSTreeNode * pListHead = NULL;//建立双向链表的头指针，指向双链表的头BSTreeNode * pListTail = NULL;//建立双向链表的尾指针，指向双链表的尾BSTreeNode *BSTreeInsert(BSTreeNode * pRoot,int value){    //为新节点申请空间并初始化    BSTreeNode *pNode = new BSTreeNode();    if(pNode != NULL)    {        pNode->value = value;        pNode->left = NULL;        pNode->right = NULL;    }    else    {   cout<<"申请内存失败！"<<endl;}    BSTreeNode * pCur = pRoot;//移动指针，用来找到当前节点要插入的位置    BSTreeNode * pParent = NULL;//移动指正，始终指向pCur的节点的父节点    if(pRoot == NULL)//当前树为空树时    {        pRoot = pNode;    }    else//当前树不为空树时    {        while(pCur != NULL)//查找当前节点在二叉查找树中应该插入的位置，pCur指向应该插入的位置，pParent指向应该插入的位置的父节点        {            pParent = pCur;            if(pCur->value <= pNode->value)            {                pCur = pCur->right;            }            else            {                pCur = pCur->left;            }        }        if(pNode->value <= pParent->value)        {            pParent->left = pNode;        }        else        {            pParent->right = pNode;        }    }    return pRoot;}void BSTree2List(BSTreeNode * pCur){    if(pCur == NULL)        return;    if(pListHead == NULL)//双链表头指针指向NULL，此时双链表尚未建立，使pHead指向pCur    {        pListHead = pCur;        pListTail = pCur;        pCur->left = NULL;    }    else    {        pListTail->right = pCur;        pCur->left = pListTail;        pListTail = pCur;    }}voidInOrderBSTree(BSTreeNode * pRoot){    BSTreeNode * pCur = pRoot;    if(pCur != NULL)    {        InOrderBSTree(pCur->left);        //二叉查找树当前节点链接到双向链表中        BSTree2List(pCur);        InOrderBSTree(pCur->right);    }}voidBSTreeNodeDestory(BSTreeNode * pListHead){    BSTreeNode *pCur = pListHead;    pListHead = NULL;    while(pCur != NULL)    {        BSTreeNode * pDel = pCur;        pCur = pCur->left;        delete pCur;        pCur = NULL;    }}intmain(int args,char ** argv){    int array[] = {6,8,4,14,16,10,12};    int len = sizeof(array)/sizeof(int);    BSTreeNode * pRoot = NULL;//建立二叉查找树根节点    //建立二叉查找树    //遍历数组中的每个元素，将每个元素作为一个树节点，插入到二叉查找树中    for(int i = 0;i < len;++i)    {        cout<<array[i]<<"  ";        pRoot = BSTreeInsert(pRoot,array[i]);    }    cout<<endl;    //二叉查找树中序遍历    InOrderBSTree(pRoot);    //打印双向链表    BSTreeNode *pCur = pListHead;    while(pCur != NULL)    {        cout<<pCur->value<<"  ";        pCur = pCur->right;    }    cout<<endl;    //销毁双向链表    BSTreeNodeDestory(pListHead);    system("pause");    return 0;}