CS 228 meeting -*- Outline -*-

* brief overview of sorting (HR 12.7-8)

	The sorting algorithms in this part of the  book
		rely more on algorithms,
		as opposed to a data structures,
		so we'll just look at it quickly

** motivating question

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          SORTING (HR 12.7-8)

          MOTIVATING PROBLEM

Given a random access collection,
arrange them in nondecreasing order.


extern void Sort( int vec[], int size );
  // PRE:  size >= 0
  // && 0..size-1 are legal indexes of vec
  // MODIFIES: vec[0..size-1]
  // POST: vec[0..size-1] contains the
  // same values as vec[0..size-1]<entry>
  // but sorted into nondecreasing order
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** overview
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          SORTING OVERVIEW

	             Average    Worst case
Techniques	     Time cost  time cost
 A. bubble           O(N^2)     O(N^2)
 B. selection        O(N^2)     O(N^2)
 C. quicksort        O(N log N) O(N^2)


Benchmark	Bubble Selection Quicksort
1000 random	127.4  80.86	 2.52
1000 sorted	0.16   85.2	 1.43

Key insight:
    Divide and conquer
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	the insight has very wide application!

	Caveat: bubble sort is actually ok if have a small number of data
		or if data are already sorted.