Nice post! I’m a little confused with the code, since it is in C. I will however make an effort to read into it a little deeper.
When I was making one in ruby, I just made an array of the whole alphabet alphabet = “abcdefghijklmnopqrstuvwxyz”.split(""), and then just referenced the values from their indexes in the array. alphabet[0] would equal a and so on. If I wanted to increment it, I would just do alphabet[alphabet.index(“C”) + rot]