CSE 109    HW 6   Due 10:45 PM  Monday  23 April 2012

     This homework is an exercise in programming in C. Write a C
     program that reads pairs of ints from the console and computes
     the greatest common divisor (GCD) of the pair. The program should
     stop reading pairs when it encounters ^D on a new line or garbage
     like 'x'.

     To submit your homework, create a subdirectory of cse109.121 called
     hw6 (that is, from your root directory, /cse109.121/hw6).  In hw6 store
     the file hw6.c Also include a Makefile for compiling hw6.c and creating
     the executable program hw6.  I will test your program with various
     input files.

     NOTE: This homework (and all homeworks) will only be collected once
     (unlike programming assignments, for which there will be multiple
     opportunities to submit your solution).

     Notes:
        (1) I have provided the file hw6.c. You should not change the
            contents of main() (except for providing the correct actual
            parameters to get()) but you should add the declarations
            (above main()) and definitions (below main()) of the functions
            get() and gcd(). I have not indicated how to parameterize get,
            but it should assign values to x and y.
        (2) You should compile your program with the following command:
               gcc -xc -Wall -Werror hw6.c
        (3) There are a number of nuisance cases when computing the GCD of
            two ints, a and b, but if a>b, then the GCD of a and b is the
            same as the GCD of a-b and b. This suggests either a recursive
            algorithm or a while statement, either of which continues until
            the two numbers are the same and the result is the GCD.

     PLEASE AGAIN READ THE SYLLABUS ABOUT UNFAIR COLLABORATION AND DO NOT
     COLLABORATE UNFAIRLY