REVISED 2/5:  simpler turnin procedure (at end)


This is the hw1 program part.  The basic goal is to implement two
different versions of the UF data structure, and compare their
performance in the "Erdos Renyi random graph" application.

It is due: 9pm Tuesday 2/7 (about one week to do it).   In fact
it is a short amount of code, but for some of you there may be
some challenge in trying BlueJ.

This is a BlueJ project.  In fact it is possible to do it outside the
lab, but here I'll describe how to start in the lab environment.

To start the project in the lab, at a terminal you want to copy
UFI.jar to your personal ~/cs323/hw1/ directory, and then open
it under BlueJ.  Like this:

userid@caribou:~$ mkdir ~/cs323/hw1
userid@caribou:~$ cd ~/cs323/hw1
userid@caribou:~/cs323/hw1$ cp ~cs323000/share/hw1/UFI.jar .
userid@caribou:~/cs323/hw1$ bluej UFI.jar &
[1] 12345
userid@caribou:~/cs323/hw1$

The BlueJ window should appear.   The goal here is that you
will finish two different implementations of the union-find
data structure, and then use the driver to compare their
performance.   The files you edit are:

   WeightedQuickUnionUF.java
   PathCompQuickUnionUF.java

The first should be weighted quick union without path compression, the
second should be path compression (or path halving) without weights.
Unlike the book, we will define these classes as subclasses of
QuickUnionUF, so you only define the data and methods that differ from
the superclass.  I don't think the book provides code for path
compression, but you can find something in the slides.

Once you think your code is working, try running ErdosRenyi.main().
You should see that they have similar performance (in my tests, half
compression is a bit faster than full compression), and both are much
faster than QuickUnionUF.  Since the path compression approach uses
half the space, it may be the best choice in low-memory situations.

Turnin: once your program is compiled and working, under the Project
menu select "Create Jar File" (NOT "Save As...").  A dialog window
pops up: select ErdosRenyi as the Main class, click both boxes (to
include source and project files), and click Continue.  Next you get a
file dialog (first time you use it, it shows your home directory).
Navigate into your ~/cs323/hw1/, and enter "sol.jar" as the File Name,
and click Create.

If you did this correctly, you should be able to run your code from
the jar file itself as follows:

   cd ~/cs323/hw1
   java -jar sol.jar


REVISED (2/5): simpler turnin procedure!

Just leave your sol.jar file in your ~/cs323/hw1/ directory, I'll take
a snapshot of those files on the deadline (9pm Tuesday).  If you do
late work, email mic@mathcs.emory.edu with sol.jar as an attachment.

REMARK: you could actually do all the BlueJ work on another computer.
Just as the last step, copy your sol.jar back onto a lab machine into
your ~/cs323/hw1/ directory (which you may need to create).