Sophomore Seminar - Programming Assignment 1

Due Tuesday, February 9th

Summary

You must write a program that uses character input and output to encrypt or decrypt a file using the ROT13 cipher. The ROT13 cipher is very simple: replace any alphabetic character with the 13th letter after it in the alphabet, rotating back to the beginning of the alphabet in the case of letters N-Z. For example, the encrypted version of

Dr. Nick

is

Qe. Avpx

Note that uppercase letters remain uppercase, lowercase letters remain lowercase, and any non-alphabetic character is left alone. One of the most interesting aspects of the ROT13 cipher is that it can also be used to decrypt text encrypted by the ROT13 cipher. You may find this useful while testing your code.

What To Hand In

Your code should be contained in a single file: rot13.c and should be emailed to me at Nicholas dot Coleman at mail dot wvu dot edu. Please also hand in a printed copy of your code in class on the due date above.