I need assistance with the following as it has been awhile since I have done any programming. (C or Java would be preferred. Leaning more towards C as it's apparently easier). Plus I have am having a bit of difficulty understanding. The affine cipher is described via another image:

Write a program that can encrypt and decrypt using the affine cipher A generalization of the Caesar cipher, known as the affine Caesar cipher, has the following form: For each plaintext letter p, substitute the ciphertext letter C: C = E([a, b], p) = (ap+b) mod 26 A basic requirement of any encryption algorithm is that it be one-to-one. That is, if p + q, then E(k, p) + E(k, q). Otherwise, decryption is impossible, because more than one plaintext character maps into the same ciphertext character. The affine Caesar cipher is not one-to-one for all values of a. For example, for a = 2 and b = 3, then E([a, b],0) = E([a, b], 13) = 3