PART 1- VALIDATION OF LUHN CODE
The goal of this part is to create a program which verifies the validity of a Luhn code. Your program should accept any given numbers after the ’-c’ flag and verify it’s validity. You must display : ‘OK’ if the number is a valid Luhn code ‘KO’ if it’s not (on the standard output). In case of an error (such as missing parameters, invalid flag, etc.), your program should display a message explaining the error on the standard error output.
PART 2- CALCULATION OF LUHN KEY
The goal of this part is add a functionality to your program: complete the code given as parameter. More specifically, you have the complete the given number by displaying the missing digit. For instance, in case of a bank number, you’ll be given the first 15 numbers and you need to find and display the 16th number