CS107 - Lab 4
Due Monday 02/22 at the beginning of class.
Some of the most important algorithms used in computing are
in the category "search and sort." These are useful in a variety of
settings, such as web search, alphabetic sorting of a list of names,
etc. They are also related, since the most efficient search
algorithms occur on lists that are sorted. This lab provides an
opportunity to explore the functioning of search and sort algorithms,
as well as their efficiency. The readings and problems for this
assignment are in Chapter 3 of your text.
Following the same steps that you used for Assignment 2, double-click
the icon csci107 - Invitation (OSX) that you copied to the
desktop. The following menu should appear:
The buttons Search Animator, Sort Animator and
Sort Timer will be useful for this assignment. When you select
either of these, you will be able to animate the behavior of several
different algorithms in Chapter 3, as well as empirically measure the
efficiency of different sorting algorithms on different amounts of
For example, select Algorithm -> Selection Sort in the
Sort Animator and then select the Run
button. You may Reset and
Rerun this exercise several times to get a feeling for how the
To count the number of exchanges and comparisons in a particular
selection sort, you can repeatedly click the Step button and keep
track of the number of times steps 9 and 6 are repeated, respectively.
Now opn the Sort Timer and select Algorithm ->
Selection Sort and Points -> 128, and then select Run.
Note that this gives the running time for selection-sorting 128 data
points, and it graphically displays the behavior of the data being
rearranged as the algorithm proceeds.
These animators will be useful for answering some of the
Algorithmic Problem Solving
Complete exercises 12, 17, 18, 19, 20, 22, 26, and 28 on pages 110-112
of your textbook.
Be sure to justify your answers! You may do this work either by
hand or with a word processor (e.g. MS Word). Also, you may choose to
do this assignment either by yourself or in a group. However,
solutions should be written up individually and handed in on Monday,
at the beginning of class.
To submit a file electronically, you should first rename it so that
you are identified as the author (e.g., give it a name like
lab-x-ltoma). Then drag the file to the csci107 -> Drop
Box folder. Be careful not to drag an entire folder into the
Drop Box; only a single file at a time can be submitted. Bring
a hard copy of your assignment and hand it in class.