Convert from Roman Numerals to Arabic

roman_numeral_converter.rb

require "pry"

ROMAN_NUMBERS = {
  "m": 1000,
  "d": 500,
  "c": 100,
  "l": 50,
  "x": 10,
  "v": 5,
  "i": 1
}

def convert_roman(string)
  total = 0
  characters = string.split("")
  characters.each.with_index do |char, idx|
    if characters[idx + 1]
      if ROMAN_NUMBERS[char.to_sym] >= ROMAN_NUMBERS[characters[idx + 1].to_sym]
        total += ROMAN_NUMBERS[char.to_sym]
      else
        total -= ROMAN_NUMBERS[char.to_sym]
      end
    else
      total += ROMAN_NUMBERS[char.to_sym]
    end
  end
  total
end

puts convert_roman("xiv")
puts convert_roman("cmxxix")