摘要：
Given a binary tree, flatten it to a linked list in-place.For example,Given 1 / \ 2 5 / \ \ 3 4 6The flattened tree... 阅读全文
摘要：
Given an array where elements are sorted in ascending order, convert it to a height balanced BST.讲一个排序好的数组转换成二叉搜索树，这题没想出来，基本上是参考别人的，边界条件应该注意一下： 1 /** ... 阅读全文
摘要：
Given acompletebinary tree, count the number of nodes.Definition of a complete binary tree fromWikipedia:In a complete binary tree every level, except... 阅读全文
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Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only 阅读全文
摘要：
Given a binary search tree, write a functionkthSmallestto find thekth smallest element in it.Note:You may assume k is always valid, 1 ≤ k ≤ BST's tota... 阅读全文