void convertNode(BSTreeNode *root, BSTreeNode ** pLastNodeInList){    if(!root)        return ;    if(root->left)    {        convertNode(root->left, pLastNodeInList);    }    root->left = *pLastNodeInList;    if(*pLastNodeInList != NULL)        (*pLastNodeInList)->right = root;    *pLastNodeInList = root;    if(root->right)    {        convertNode(root->right, pLastNodeInList);    }}BSTreeNode *convert(BSTreeNode* root)//true = right, false = left{    if(!root)        return root;    BSTreeNode* pLastNodeInList = NULL;    convertNode(root, &pLastNodeInList);    while(pLastNodeInList && pLastNodeInList->left)    {        pLastNodeInList = pLastNodeInList->left;    }    return pLastNodeInList;}

输入一个二叉搜索树，将该二叉搜索树转换成一个排序的双向链表。不能创建任何新的结点，只能调整树中结点指针的指向。