How would you create a C++ program to do encoding and decoding of messages using the Vignere cipher using public and private classes? The message to be encoded must only consist of uppercase letters and the keyword should also be only upercase. Whitespace should not alter the encryption, so if you were encoding three words, the output should be the same regardless of the words being entered on one line or three. The program should require exactly two command line arugments. The first will either be the code “-e” or “-d” to indicate ecoding or decoding of a message (this determines adding or subtracting your shift values) and the second paramter will be a single word that will be the keyword that you use for the encryption or decryption.
To test, encoding “This is a test.” using keyword CSELEVEN would output “VZMDMNEGGKX”