santa2.rb

def decode_message(input)
  words = input.split("\n")
  letters = [{}, {}, {}, {}, {}, {}]
  words.each do |word|
    word.each_char.with_index do |char, index|
      if letters[index].key?(char)
        letters[index][char] = letters[index][char] + 1
      else
        letters[index][char] = 1
      end
    end
  end
  letters.map { |letter| letter.key(letter.values.max).to_s }.join
end

decode_message('eedadn
drvtee
eandsr
raavrd
atevrs
tsrnev
sdttsa
rasrtv
nssdts
ntnada
svetve
tesnvt
vntsnd
vrdear
dvrsen
enarar')