CSE 331: Homework 3 Spring 2009
Due by 11:59 PM Friday 6 Feb 2009
Submission
Submit your work via Handin. Name your file <name>Results.pdf, where
<name>is your last name, as in jonesResults.pdf. Please make sure that your
name and your MSU net ID appear at the top of every page and once at the
beginning of any code that you may submit.
Problems:
Do the following problems from Chapter 7 of the text. As always, we do not
want just the “answers”, we want the reasoning behind the answers.
1. (35 points) Show how the quick-sort algorithm (page 286, but do not call
insertion sort) sorts the following list: [ 64, 12, 34, 44, 86, 3, 7, 55, 99, 11,
41]. The purpose of this assignment is to help you understand how the
quicksort algorithm works, in detail.
Draw the calling diagram as a tree.
(a) The root is the original call.
(b) Use median3 with no randomness (i.e. left, right, center) in calculat-
ing the result.
(c) Show each list after the median3 step.
(d) Show each list after the swap step.
(e) Give the parameters of every call to quicksort.
(f) The order of the numbers needs to be correct at every step.
(g) After each median step and swapping step, the pivot should be de-
noted in some way.
(h) It is not necessary to show the quicksort step on a list of three num-
bers or less. Similarly, it’s not necessary to show the median step on
a list of a single number.
(i) For this exercise implement the quicksort exactly as it is in the book
although there are other, alternative, ways to do quicksort.
(j) Do not use insertion sort at all, even though the algorithm in
the book on page 286 does for smaller inputs.
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