Given a linked list, remove the n-th node from the end of list and return its head.
给定链接列表，从列表末尾删除第n个节点并返回其头部。

Given a string, find the length of the longest substring without repeating characters.
给定一个字符串，找到最长子字符串的长度而不重复字符。

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 endpoints of line i is at (i, ai) and (i, 0). Find two lines, which together with x-axis forms a container, such that the container contains the most water.
给定n个非负整数a1，a2，…，an，其中每个表示坐标（i，ai）处的点。 绘制n条垂直线，使得线i的两个端点位于（i，ai）和（i，0）。 找到两条线，它们与x轴一起形成一个容器，这样容器就含有最多的水。

You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.

You may assume the two numbers do not contain any leading zero, except the number 0 itself
您将获得两个非空链表，表示两个非负整数。 数字以相反的顺序存储，每个节点包含一个数字。 添加两个数字并将其作为链接列表返回。

您可以假设这两个数字不包含任何前导零，除了数字0本身

继承

初始化，宏定义，常函数和静态成员

函数重载和默认参数，拷贝构造，符号重载

析构函数，构造函数，友元和接口函数等

指针，引用，引用变量，引用做参数和返回值，指针和引用的区别

一些基础知识点，结构体和类理论