摘要：
Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 涉及到二叉树的问题用递归的方法很容易理解。这个问题要求把一个升序排序的链表转换为 阅读全文
摘要：
Given a binary tree, flatten it to a linked list in-place. For example,Given The flattened tree should look like: 阅读全文