题目27：二叉搜索树与双向链表

1 struct BinaryTreeNode
2 {
3     int m_nValue;
4     BinaryTreeNode* m_pLeft;
5     BinaryTreeNode* m_pRight; 
6 };

 1 BinaryTreeNode* convert(BinaryTreeNode* pRootOfTree)
 2 {
 3 　　//pLastNodeList指向已经转换好的链表的最后一个结点
 4 　　BianryTreeNode* pLastNodeInList = NULL;
 5 　　convertNode(pRootOfTree, &pLastNodeInList);
 6 　　//pLastNodeInList指向双向链表的尾结点，需要找到头结点
 7 　　BianryTreeNode* pHeadOfList = pLastNodeInList;
 8 　　while (pHeadOfList != NULL && pHeadOfList->m_pLeft != NULL)
 9 　　　　pHeadOfList = pHeadOfList->m_pLeft;
10 　　return pHeadOfList;
11 }
12 
13 void convertNode(BinaryTreeNode* pNode, BinaryTreeNode** pLastNodeList)
14 {
15 　　if (pNode == NULL)
16 　　　　return;
17 　　BinaryTreeNode* pCurrent = pNode;
18 　　if (pCurrent->m_pLeft != NULL)
19 　　　　convertNode(pCurrent->m_pLeft, pLastNodeList);
20 　　pCurrent->m_pLeft = *pLastNodeInList;
21 　　if (*pLastNodeInList != NULL)
22 　　　　(*pLastNodeInList)->m_pRight = pCurrent;
23 　　*pLastNodeInList = pCurrent;
24 　　if (pCurrent->m_pRight!=NULL)
25 　　　　convertNode(pCurrent->m_pRight, pLastNodeList);
26 }