CpSc 241, Section 1
                             Assignment 5
                           16 February 2000


Due: Wednesday, February 23 at midnight

Late penalties: 20 points per partial day late.  That is, programs
	turned in after midnight Wednesday and before midnight Thursday
	will have 20 points deducted for late, programs turned in after
	midnight Thursday and before midnight Friday will have a total
	of 40 points deducted for late, etc.

Total point value of assignment:  100 points

Late submissions not accepted after: Saturday, February 26 at midnight

This assignment is to be done INDIVIDUALLY.


Create a directory, A5, which will contain all parts of this assignment.
You will need class ListNode, class ListItr, and class List from the text. 
You will also need

	a5.cpp (your main program)  

The objectives of this program are to give you more experience with
program design and with traversing a list.

The main() will be called a5.cc or a5.cpp, whichever you choose.  Submit
all files in directory A5 using handin.


Part I:  You are to design a method, retreat(), which is to be part
	of the ListItr class.  When you design this method, you will
	discover a reason why you cannot simply insert the retreat
	method in the class.  Hint:  Try drawing a picture of a List
	with a ListItr referencing some node half-way down the List.
	After you have written your code, trace the action of your
	code on the List.  Why does it not work?

	If itr is an object of type ListItr, a call to retreat will
	look like
				itr.retreat( );

	If you can't figure out why the code will not work by tracing
	with paper and pencil, your last resort will be to type in the
	code and let the system tell you why it won't work -- maybe.

	After you figure out why your code won't work, email your
	instructor and tell her why it won't work.  Also suggest what
	you could do to the ListItr class so that retreat would work.

	Do not change either the List class or the ListNode class.

	********** Part I MUST BE COMPLETED BY MONDAY NIGHT **********


Part II:  Write a main program called a5.cpp that thoroughly tests
	the retreat code.
	

Other requirements:

	Follow the style standards to be found from your instructor's
	web page for CPSC 241.


Grading rubric:

	Maximum of 10 points (out of 100) awarded for retreat in List class.

	Part I:  30 points.  Must be before deadline.

	Style standards, including required documentation 20 pts.
	Program compiles without errors.  10 pts.

	If the the program does not compile without error, no further points
		will be awarded.

	Logically correct choice for retreat past beginning of List 10 pts.
	Retreat works correctly for some, but not all, situations 10 pts.
	Retreat works all the time 30 points.