Please complete the following challenge and submit your response in a gist.
Write your code with the following priorities in mind, in order from most to least important:
- Correctness and completeness
- Clarity and readability
- Conciseness and performance
Without further ado:
A rotational cipher, ROT(X), is an ancient encoding that, given a message, returns a message where each letter has been replaced by the letter exactly X letters after it in the alphabet ordering. Letters near the end of the alphabet wrap around. For example, the translation table for ROT(13) looks like:
ABCDEFGHIJKLMNOPQRSTUVWXYZ
NOPQRSTUVWXYZABCDEFGHIJKLM
and therefore the message HELLO becomes URYYB
Please implement rotx in Ruby, which given a rotation number and a string, outputs the string rotated by that many letters. It should preserve capitalization and ignore any non-alphabetic character. It should also take a parameter that decrypts the string instead of encrypting it. For example:
def rotx(x, string, encrypt=true)
# Your implementation here...
end
rotx 10, 'Hello, World'
# => "Rovvy, Gybvn"
rotx 10, 'Rovvy, Gybvn', false
# => "Hello, World"
# Rotation numbers greater than 26 should work as well
rotx 36, 'Hello, World'
# => "Rovvy, Gybvn"Good luck!
Side note: you could find plenty of examples of this code online. Since this is a test of our candidates' ability to solve problems rather than search Google for solutions, we ask that you complete this challenge without checking someone else's implementation.