摘要: Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree [1,2,2,3,4,4,3] is symmet 阅读全文
posted @ 2019-03-02 13:34 TobicYAL 阅读(132) 评论(0) 推荐(0) 编辑
摘要: Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. Example 1: Example 2: Follow up: A 阅读全文
posted @ 2019-03-02 13:18 TobicYAL 阅读(152) 评论(0) 推荐(0) 编辑
摘要: 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
posted @ 2019-03-02 11:26 TobicYAL 阅读(187) 评论(0) 推荐(0) 编辑