Homework Assignment 5
                               CS 340d
                         Unique Number: 50960
                             Spring, 2019

                       Given:  February 25, 2019
                          Due:  March 6, 2019


1.  This problem is a further evolution of Problem 1 from HW #3 and HW #4.
    Our specification remains the same:

    char *dst, *src;
    // Set src and dst pointers
    while( *dst++ = *src++ );

    This program fragment copies memory bytes from *src to *dst one
    byte at a time.

    Unlike Problem 1 from HW #3 and HW #4, we no longer know that the
    initial value of pointer ``src'' and ``dst'' are long-word (8-byte)
    aligned.  If they are, then the solution you produced for Problem 1
    of HW #3 should (hopefully) work.  But, if the starting point of
    ``src'' and ``dst'' are not 8-byte aligned, then you will need to do
    some additional work.

    Your solution should not read each word from the memory referenced
    by ``src''  more than once and should not write each word referenced
    by ``dst'' more than once.

    Be sure to specify a loop invariant and a termination condition for
    all forms of your memory copy program.


2.  Write a C-language program which converts ASCII to EBCDIC and also
    converts EBCDIC to ASCII.  Your program should read input from
    stdin and write the converted output to stdout.  You do not need
    to parse filename arguments on the command line, just read from
    stdin and write to stdout.

    Your program should include an invariant which specifies when the
    EBCDIC-to-ASCII conversion will be lossless. It should also
    include another invariant which specifies when the ASCII-to-EBCDIC
    is lossless.  When the conversion will not be lossless, the return
    status should be a negative number.

    When supplying this program with ASCII input that can be converted
    to EBCDIC in a lossless manner, it should also be possible to
    convert that EBCDIC back to ASCII in a lossless manner.


3.  Turn in your C-language code for the predicate for Part B of Lab
    #1.  This predicate should identify a unique representation of a
    2-dimensional set.  This is a way for you to get early feedback on
    your Lab #1 effort.