CpSc 210, Section 1
                             Assignment 11 
                            November 18, 2002


Due:  Tuesday, November 26 at 11:59 p.m.  
Accepted without penalty until:  Wednesday, December 4 at 11:59 p.m.
NOT ACCEPTED after Wednesday, December 4 at 11:59 p.m.

Assignment:  Add an external iterator for the ArrayList class.  This
     external iterator reference the ArrayList, but storage requirements
     for the iterator are O(1).  i.e., storage requirements are constant.

Total point value of assignment:  50 points Extra Credit

This assignment is to be done INDIVIDUALLY.

Assignment:  Your ArrayList.java file needs to have the following:

	import structure.QueueArray     // Bailey's QueueArray implementation
	import structure.List;          // Bailey's List interface
	import structure.Iterator;      // Bailey's Iterator interface

	public class ArrayList extends QueueArray implements List
	{

We may run your iterator against our class ArrayList instead of yours.
Do not assume that head will be at index zero.  The value of head
should be as defined in Assignment #7.  

You will need to code the elements() method to your ArrayList class.
In a separate file (ArrayListIterator.java) implement an external
iterator for the ArrayList.  You will need:

	import structure.Iterator

	public class ArrayListIterator implements Iterator
	{


The Iterator interface is given on page 157 of Java Structures.  Your
program should include every method of the interface.  The elements
method should send whatever parameters are needed to the constructor
for the iterator.  

You will submit both ArrayList.java and ArrayListIterator.java at
the same time using the handin command.  Even if your previous
ArrayList.java worked perfectly, submit it again, this time to
Assignment 9.


Grading Rubric:

     5 pts. reasonable attempt to solve problem as assigned
     5 pts. also compiles (both classes)
     5 pts. style standards (includes clarity, comments, etc.)

    The following points are available only for code that compiles 
    and runs without runtime error.   Some requirements are:

    25 pts. elements() method does NOT copy array from ArrayList.  
            Instead, a reference to the array must be passed.  Only simple
            variables and references are passed to Iterator 
            and code works correctly.
       
     5 pts. elegance of code

     5 pts. include a test driver that has three iterators concurrently
	        traversing the same list.