1.把二元查找树转变成排序的双向链表[BST2DoubleLinkedList]

【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。

比如将二元查找树 。

10

/ \

6 14

/ \ / \

4 8 12 16

转换成双向链表

4=6=8=10=12=14=16。

【代码】：

C++ Code

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/////////////////////////////////////////////////////////////////////// // Covert a sub binary-search-tree into a sorted double-linked list // Input: pNode - the head of the sub tree // pLastNodeInList - the tail of the double-linked list /////////////////////////////////////////////////////////////////////// void ConvertNode(BSTreeNode *pNode, BSTreeNode *&pLastNodeInList) { if(pNode == NULL) return; BSTreeNode *pCurrent = pNode; // Convert the left sub-tree if (pCurrent->m_pLeft != NULL) ConvertNode(pCurrent->m_pLeft, pLastNodeInList); // Put the current node into the double-linked list pCurrent->m_pLeft = pLastNodeInList; if(pLastNodeInList != NULL) pLastNodeInList->m_pRight = pCurrent; // Update the last node in list pLastNodeInList = pCurrent; // Convert the right sub-tree if (pCurrent->m_pRight != NULL) ConvertNode(pCurrent->m_pRight, pLastNodeInList); } /////////////////////////////////////////////////////////////////////// // Covert a binary search tree into a sorted double-linked list // Input: pHeadOfTree - the head of tree // Output: the head of sorted double-linked list /////////////////////////////////////////////////////////////////////// BSTreeNode *Convert_Solution1(BSTreeNode *pHeadOfTree) { BSTreeNode *pLastNodeInList = NULL; ConvertNode(pHeadOfTree, pLastNodeInList); if (pLastNodeInList != NULL) pLastNodeInList->m_pRight = NULL; // Get the head of the double-linked list BSTreeNode *pHeadOfList = pLastNodeInList; while(pHeadOfList && pHeadOfList->m_pLeft) pHeadOfList = pHeadOfList->m_pLeft; return pHeadOfList; }

【参考】：

/article/2783023.html

http://www.cnblogs.com/wolenski/archive/2012/07/08/2581859.html