摘要：
题目： Given a binary tree, return the preorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, return [1,2,3]. 题意及分析：给出一个二叉树，求先 阅读全文
摘要：
题目： Given a binary tree, return the zigzag level order traversal of its nodes' values. (ie, from left to right, then right to left for the next level 阅读全文
摘要：
题目： Given a binary tree, return the inorder traversal of its nodes' values. For example:Given binary tree [1,null,2,3], return [1,3,2]. 题意及分析：简单来讲就是给出 阅读全文