CSC151 2007S, Class 49: Merge Sort

Admin:
* Are there questions on the exam?
* No readings for the rest of the week (project discussion).
* EC: Today's noon talk on convicting criminals through stats.
* Projects available at
  http://www.cs.grinnell.edu/~rebelsky/Courses/CS151/2007F/Projects/Submissions/

Overview:
* Analyzing insertion sort
* More efficient sorting techniques.
* Divide and conquer, revisited.
* Merge sort.
* Analyzing merge sort.

Insertion Sort
* Have two lists: Unsorted and sorted
  * Unsorted is initially "everything"
  * Sorted is initialy "nothing"
  * Grab something from the unsorted list and put it into the sorted list
* Question: How efficient is this algorithm?
  * Answer technique 1: Make the program count for you
  * Answer technique 2: Analyze Abstractly

[Sam uses the physical whiteboard to discuss how you examine efficiency]

Lab!