number_to_words.rb

CONVERSION_HASH = {
  1 => "one",
  2 => "two",
  3 => "three",
  4 => "four",
  5 => "five",
  6 => "six",
  7 => "seven",
  8 => "eight",
  9 => "nine",
  10 => "ten",
  11 => "eleven",
  12 => "twelve",
  13 => "thirteen",
  14 => "fourteen",
  15 => "fifteen",
  16 => "sixteen",
  17 => "seventeen",
  18 => "eighteen",
  19 => "nineteen",
  20 => "twenty",
  30 => "thirty",
  40 => "forty",
  50 => "fifty",
  60 => "sixty",
  70 => "seventy",
  80 => "eighty",
  90 => "ninety",
  100 => "one hundred"
}


def number_to_words(number)
  return "Number to large" if number > 100
  tens, ones = number.divmod(10)
  return CONVERSION_HASH[number] if tens == 1
  "#{CONVERSION_HASH[tens * 10]} #{CONVERSION_HASH[ones]}"
end

ARGV.each do |arg|
  puts number_to_words(arg.to_i)
end