CSE 109   Program #0   Due 10:45 PM Thursday 2 February 2012
Late collections:  10:45 PM 4 February 2012, 5 February 2012

In this assignment I ask you to develop a class whose objects are meant
to implement the Abstract Data Type (ADT) for a "frequency distribution,"
which counts the occurences of items in a fixed number of categories.
For example, the grades A, B, C, D, and F denote 5 categories, and we
could construct a frequency distribution for the number of As, Bs, Cs,
Ds, and Fs earned in CSE 109 last semester.

In /proj/csc109/p0 I have stored the file p0.cc, which is a driver for
testing your class Frequency that implements the ADT for a frequency
distribution.  The file p0.cc has, at the bottom, the output that was
produced when it was run using my implementation of Frequency.  Further,
I have stored the file 'Makefile' in /proj/csc109/p0. You should copy the
files  /proj/csc109/p0/p0.cc and /proj/csc109/p0/Makefile into your
directory cse109.121/p0 (a directory you should create).  You should do 
all your work in the directory cse109.121/p0.  A little green man, or his
wife, will collect your work from there.

You should add to p0.cc your declaration of class Frequency (before main()),
as well as the definitions (code) (after main()), BUT DO NOT CHANGE THE
*CODE* THAT I WROTE IN p0.cc AT ALL (BUT IT IS VERY IMPORTANT THAT YOU DO ADD
DOCUMENTATION). DO NOT CHANGE THE CODE THAT I WROTE IN ANY WAY, but ADD
DOCUMENTATION (name, assignment, program purpose, etc.,) AND YOUR OWN CODE
AND DOCUMENTATON FOR THE CLASS Frequency. I will test your class Frequency by
compiling and running your p0.cc. (The command 'make' will use the Makefile to
do the compilation)

When you are ready to submit your work, create the file "DONE" by executing
the command "touch DONE".

Notes: 1. Both your file p0.cc and your makefile, should have good
         documentation.  Both files should have identifying information at the
         top, e.g., your name, the course, the assignment number.
         Your class should be documented with comments at the top which
         explain the class and its purpose.  The role of each data member
         should be explained.  Each function and operator should be explained
         (e.g., by stating pre- and post-conditions and by stating the overall
         algorithm).  Hard to to understand sections of the code (definitions)
         should be explained. Normally, the bulk of the documentation belongs
         with the declarations. The only documentation in the code should be
         that needed to explain hard to follow code. Note: The documentation
         for the class and its data and methods should be with the
         declaration above main(), not the definitions below main().

       2. You should be able to determine the functionality of the class
         Frequency by looking at the code in main() and the output that I got
         when I did this programming assignment, but do note that
             operator[] gives access to the j category but does not allow
                        it to be changed
             add()      increases the frequency in a given category
             sub()      decreases the frequency in a given category
             total()    gives the sum of all the frequencies
             percent()  gives the (int) percentage (e.g., 23) of the
                        total in a given category
             getSize()  returns the number of categories
             operator+  returns a new distribution by adding the
                        corresponding frequencies in the two distributions,
                        except that it crashes the progrm if you try to
                        sum distributions whose number of categories differ


       3. Lehigh claims that you should work, on average, three hours
         outside of class for every hour spent in class. In this course,
         you are likely to meet or exceed that average. This STRONGLY
         SUGGESTS it is not wise to wait until the last minute to do the
         assignment. If you work ahead and get stuck, you can email me
         and get help. At the last minute, I probably will not read your
         email, having gone to bed.

       4. A careful examination of my output (at the bottom of p0.cpp)
         should lead you to conclude that the default size (and maximum
         size) of any instance of Frequency is 20 categories.

IN THE SYLLABUS READ THE STATEMENT ABOUT UNFAIR COLLABORATION AND AVOID
UNFAIR COLLABORATION