Computer Science 15-100 (Sections T & U), Fall 2007
Homework 9
Due:  Fri 7-Dec-2007 at 8:30am (email copy) and at recitation (physical copy)

• Be sure to include your name, your Andrew ID, and your section (T or U) clearly on the top of your assignment (both written and electronic)!
   
• Your submission (electronic and physical) will include these files:
  • Hw9Q2_1.java
  • Hw9Q2_2.java
  • Hw9Q3.java
  • Hw9Q4.java
  • Hw9Q5.java

1. Read L&L Chapters 8 (8.1 - 8.5) and 9 (9.1 - 9.6) and study the relevant Key Concepts and the Self-Review Questions and Answers.  Do not submit these.
    
2. Do the following Programming Problems from L&L:
   1. Any one of these:  PP 8.2, 8.3, 8.4, 8.5, 8.11, 8.12, 8.13
   2. Bonus [optional]:  PP 8.9
       
3. Here you will make a simple animation.  To do this, start from BasicGraphicsWithTimer.java.  This is just like BasicGraphics.java, but it includes the code we need for simple animations.  In particular, it has a method called "onTimer" that will be called at regular intervals (if you look closely at the code, you will see how you can control how frequently this method is called).  To animate a graphical object, just make some of its properties into instance variables, and then change those instance variables inside the onTimer method.  The included example shows how to animate a yellow circle so it moves across the screen repeatedly.  Study this example and be sure you understand how it works.  Then, create the following animation:
   
    
4. PP 9.6 (but do it for bubblesort instead of selection sort, and do this using the animation technique you just learned in the previous exercise).  Basically, you are implementing your own simplified version of xSortLab.
    
5. BONUS [optional -- worth 20 pts]:  Generalize PP 9.6 so that it uses classes and inheritance to work for several other sort algorithms (bubblesort, insertion sort, and selection sort).  To do this, create a class named SortAnimator that does the main animation.  This class's constructor should take a SortAlgorithm instance.  SortAlgorithm should be an abstract class, where a SortAlgorithm should have a method setArray(int[] array), that sets the array to be sorted, and then a method step().  The step method should return an instance of SortStep, which describes what the sort array will do in the next step as it sorts the given array.  A "step" may be something like comparing two elements, swapping two elements, etc.  The SortAnimator will create a SortAlgorithm instance, give it a random array, and then repeatedly call its step method and display the result.  Naturally, BubbleSort, SelectionSort, and InsertionSort are all subclasses of SortAlgorithm.  The rest is up to you....  :-)

Carpe diem!