摘要：
Given a binary tree, return the preorder traversal of its nodes' values. Example: Follow up: Recursive solution is trivial, could you do it iterativel 阅读全文
摘要：
Given two binary trees, write a function to check if they are the same or not. Two binary trees are considered the same if they are structurally ident 阅读全文
摘要：
Given a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom. Example 阅读全文
摘要：
Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree [3 阅读全文