对于快速排序过程中一个的问题：为什么在qsort中递归时，需要将递归范围改为[lo, pos-1]而不是[lo, pos]?

归并排序和快速排序是两个经典的分治算法的应用。

普通的二叉查找树(二叉搜索树)依赖于输入数据的随机性。如果输出的是预先排序的数据，就会导致单支树的出现，这时效率会急剧下降。

括号系列的几道题，涉及到括号匹配，生成括号等等．

IPC（进程间通信，InterProcess Communication）

进程间通信方式有管道、

此文档主要整理并记录liunx中常用的api．

TCP的状态转换

Given a binary tree, find its minimum depth.

Given a list of non-negative numbers and a target integer k, write a function to check if the array has a continuous subarray of size at least 2 that sums up to a multiple of k, that is, sums up to nk where n is also an *integer**.

Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.

(i.e., [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,2]).