Assignment #4 - 97A

Assignment 4
==============                                                          hhal

T.A          : 

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               Send your 'C' source file, your data and output to your code HC--
               on MUSICB.
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Due          : 25 October 1997
Weight       : 25

            SOCIAL  INSURANCE NUMBER VALIDATION PROGRAM
            ___________________________________________


   Write a 'C' program to validate the accuracy of any Social
   Insurance Number (SIN). ( or to impress others by guessing the
   last digit, given the first eight digits ).

   The Social Insurance Number contains nine digits. ( the first
   eight digits are assigned, while the ninth is constructed from
   the first eight, and therefore acts as a check-digit).

   Ex: SIN =  1    9    3    4    5    6    7    8    7
             1st  2nd  3rd  4th  5th  6th  7th  8th  check-digit

   Steps: ( High Level Specifications ).
          ______________________________

   (1) Construct a 4 digit number from the 2nd, 4th, 6th and 8th
       digit of the SIN.         ie. 9 4 6 8

   (2) Multiply the constructed digit in step (1) by two.
                                 ie. 9 4 6 8   *  2  = 1 8 9 3 6

   (3) Cross add all the resulting digits of step (2).
                                 ie. 1+8+9+3+6   = 27

   (4) Construct a 4 digit number from the 1st, 3rd, 5th and 7th
       digit of the SIN          ie. 1 3 5 7

   (5) Cross add all the resulting digits  of step (4).
                                  ie. 1+3+5+7 = 16

   (6) Add the results of step (3) and (5) together.
                                 ie. 27 + 16 = 43

   (7) If the result of step (6) is a multiple of 10 then
          the check digit is 0
       Otherwise the check is 10 - MOD(results of step (6) , 10 )
                                 ie. 10 - MOD(43,10) = 7

       Test you program on the following SIN numbers:

       111111111
       222222222
       333333333
       444444444
       555555555
       666666666
       777777777
       888888888
       999999999
       205446651
       193456787
       your own number (optional)
       3 more numbers (be creative)...

       Requirements:

       1) Do NOT use arrays.  Call the digits d1 d2 d3 ... d9
       2) Use a simple while loop - you will be shown this in class.
       3) Nicely formatted output, with message and correct check digit, as
          below.

       S.I.N            Message       Correct Check-Digit
       _________        _______       ___________________

       111111111        Wrong SIN            8
       222222222        Wrong SIN            6
       333333333        Wrong SIN            4
       444444444        Wrong SIN            2
       555555555        Wrong SIN            6
       666666666        Wrong SIN            4
       777777777        Wrong SIN            2
       888888888        Wrong SIN            0
       999999999        Wrong SIN            8
       205446651        Correct SIN          1
       193456787        Correct SIN          7
       your own number (optional)
       3 more numbers (be creative)...

       your program should prompt the user for a Social Insurance Number,
       validate it, and print the Message as above, with the Correct
       Check-Digit.

       Your program should loop until the user enters a special character
       as a social insurance number, or a SIN of 0.

 NOTE: We assume that if the Check-Digit is correct, then the SIN is
       a valid number.