算法经典- 算法导论（Introduction to Algorithms)

作者 Thomes Cormen, Charles Leiserson, Ronald Rivest, Clifford Stein. 去四位作者名称首字母，简写为 CLRS。

The book starts with an algorithm analysis of sorting algorithms.

In chapter 3 they provide definition of time/space complexity of algorithms.

Chapter 4. Divide and Conquer.

Using the idea of divide and conquer they introduces the classic sorting algorithms: heap sort and quick sort.

Heap sort: based on a basic data structure: complete binary tree.

Key: heap-maxify. using it recursively.

Quick sort: worst case: O(n^2). But it works very well practically.

Key: the choice of petition value.