Caesar Cipher

caesar_solve.rb

def shift(str, n)
    before = [*'a'..'z'].join
    after = [*'a'..'z'].rotate(n).join
    str = str.tr(before, after).tr(before.upcase, after.upcase)
    return str
end

str = 'Myxqbkdevkdsyxc, iye wkno sd!!'
26.times{|i|
    puts "#{i}: #{shift(str,i)}"
}