摘要：
Given a non-empty binary tree, return the average value of the nodes on each level in the form of an array. Example 1: （1）思想1：使用queue ，对二叉树进行层遍历。 C++： 阅读全文
摘要：
Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpo 阅读全文