CS 226
Homework 5
Due Monday March 19

Note: The TA asks that you also put your email address on your
homework to make it easier to associate people's written and
programming work.

Written:

R-5.9
C-5.4
R-6.1
R-6.10
R-6.20
C-6.5
C-6.12

Programming:

   Do problem P-5.3 (ou may find the stack from your previous
assignment useful here).

In addition, I would like you to implement an iterator for the
stack and use it to print the contents of the stack.  Here is what I
would like to see:

  1) Call your main class Postfix.

  2) Extend your stack to an IterableStack that implements the
     iterable interface. This is, it should have an iterator() method
     that returns an iterator on elements. You can import the interface
     for iterators using java.util.Iterator.

  3) Create an iterableToString method in the Postfix class that would
     have the following declaration

     public String iterableToString(Iterable<E> x)

     This method should return a string of the stack contents. It
     should use the special Java iteration syntax for iterators.

  4) Now, at each step of postfix evaluation, I would like you to print
     the contents of your stack using your iterableToString function

  
For example, if the input string is

6534+*+

The output would be 

6
6,5
6,5,3
6,5,3,4
6,5,7
6,35
41