CIS 350 Assignment 1
                          Fall 2000

     For your first assignment you will have the opportunity to 
explore object-oriented programming as a means of implementing 
stacks and queues. In simulations, waiting lists are implemented 
using either a LIFO or FIFO policies. Your task will be to write 
a client program that allows the user to determine at run-time 
whether a given item in a 6 element array is to be managed using 
a LIFO or FIFO policy for simulation purposes.

     Under a LIFO policy new items are pushed onto a stack and 
are removed by popping items off the stack. Under a FIFO policy 
new items are enqueued and dequeued from a queue. To allow the 
user to determine a run-time that policy will be used for a given 
item, you will need to declare stack and queue objects as 
descendants from a common ancestor. The ancestor type (or base 
class) will also serve as the basis to declaring the array 
element type.

     Your programming task is to implement a stack class, a queue 
class, a common ancestor class, and an array class. You will then 
need to write a client program that demonstrates the degree to 
which your stack and queue objects can be used interchangeably. 
For example, you might define a procedure, which display the 
contents of the stack or queue passed as its input parameter. You 
also should devise experiments which demonstrate the weaknesses 
of your implementations (e.g. "extra" method calls which are not 
part of the stack ADT specification). Your output must display 
information with sufficient detail to make it possible for me to 
trace the execution of your program.

     You may do your work on Unix or on a PC. You may write your 
programs using C++ or Java. Your solution must involve the 
implementation of the stack, queue, and array ADT's as object 
classes descended from a common ancestor (perhaps some list or 
table type). As mentioned in class, the only operations allowed 
on instances of stacks or queues, are the methods defined for 
their classes (i.e. type cheating is not allowed). Your ADT's 
must be implemented in using C++ classes or their equivalent. Do 
not forget what you were taught about structured programming and 
top-down modular design (and testing) in CIS 200.

     You will need to turn in a properly commented source listing 
of your problem solution, which includes the messages generated 
by the compiler. You will also need to turn in the sample run, 
along with a 3 to 5 page memo describing your solution with 
emphasis on the data structures used and a discussion of the 
efficiency of your solution (including relevant "big-Oh" type 

Assigned: 9-19-00
Due date: 10-10-00