CpSc 210, Section 1
                             Assignment 9 
                             26 June 2000


Due: Monday, June 26 at midnight

Late penalties: 20 points per partial day late.  That is, programs
	turned in after midnight Monday and before midnight Tuesday
	will have 20 points deducted for late. 

Total point value of assignment:  100 points

********** NOTE:  Not accepted after Tuesday midnight **********
Late submissions not accepted after: Tuesday, June 27 at midnight

This assignment is to be done INDIVIDUALLY.



Create a directory, A9, which will contain all parts of this assignment.
The directory will contain a class named asg9.java, which contains
your main program.  You will also need

	a class that extends Bailey's BinaryTree class (which will
	     contain a constructor and an elements method).  Your 
	     binary tree in asg9.java will be of type ExtBinTree
	     (see at end of assignment description.)

	a class that implements the Iterator interface

The objectives of this program are to give you some experience writing
working with a binary trees and iterators.

You are to construct a postorder iterator which does not keep a
stack, queue, or any other container.  The nextElement() method will 
not be recursive.  Instead, current "knows" where it is in the
tree and nextElement() reassigns current appropriately.

 
Input:

 	None required, but your main method may input values if
	you wish.

Output:

	Print your name, the assignment number, and a short description
	of the assignment to the screen.

	Your main method should construct a (fairly complex) binary
	tree (of type ExtBinTree), invoke Bailey's preorder, inorder,
	postorder, and level order iterators and then invoke your
	postorder iterator.


Other requirements:

	Follow the style standards to be found on your instructor's
	web page for CPSC 210.

	Submit your program using the handin command.  There is a link to
	the handin description on your lab page (www.cs.clemson.edu/~lab210).


Grading rubric:

	Required documentation and style standards:  20 pts.

	The program compiles without error   10 pts.

	Program must compile for further points to be awarded.
	   (Max points for programs that don't compile: 20)

	Test tree contains at least 10 BinaryTreeNodes and is
	   not completely symmetric or completely balanced.
       10 pts.

 	Required (your) iterator works correctly.  50 pts.

	Quality of test program:  10 pts.

-------------------------------------------------------------------------


   
import structure.*;

public class ExtBinTree extends BinaryTree
{

   public ExtBinTree()
   {
      super();
   }

   public Iterator EBTElements()
   {
      return new MyPostIterator(this.root);
   }
}