Programming Puzzle #2

Hello Computer Scientists! Here is the puzzle for the week of September 30th: cryptography! Beginner level: can you take in a string using the “input” command and print it out backwards? You can use the same program to “decrypt” your message! Level 2: Hail Caesar! Your second-best spy sent you the following two messages. Can you write a program that decrypts them? The only information you have is that they are encrypted using two Caesar Cyphers: “Ugfyjslmdslagfk! Qgm vav lzw xajkl gfw ugjjwuldq!” and “Xli iriqc ampp exxego ex hear!” Level 3 challenge: your best spy sent you this text file: http://www.bartucz.com/mrbartucz/a_encrypted.txt You know that each letter is matched consistently with a different letter, but not in a regular way (i.e. not Caesar). So for example, “a” might be matched with “P” and “R” might be matched with “g” (and yes, capitals and lowercase of the same letter might have different matches). But you’ve lost your code book. Is there any way to decode it?