Converts integers to Roman numerals.

nums_subtraction.rb

def numerals_subtraction(int)
  values = %w(M D C L X V I)
  
  roman_num = ""

  values = {"M" => 1000, "D" => 500, "C" => 100, "L" => 50, "X" => 10, "V" => 5, "I" => 1}

  values.keys.each do |i|
    if (int % values[i]) then

      roman_num << i*(int / values[i])  # Equal to the quotient
      remainder = (int % values[i]).to_s
      msd = remainder[0].to_i
      print "i = #{i}, int = #{int}, values[i] = #{values[i]}, int/values = #{int/values[i]} , msd = #{msd}\n" 

      if msd == 9
        if (remainder.length == 3)
          roman_num << "CM"
          int = int - 900
        elsif (remainder.length == 2)
          roman_num << "XC"
          int = int - 90
        else
          roman_num << "IX"
          int = int - 9
        end        
      elsif msd == 4
        if (remainder.length == 3)
          roman_num << "CD" 
          int = int - 400
        elsif (remainder.length == 2)
          roman_num << "XL" 
          int = int - 40
        else
          roman_num << "IV"
          int = int - 4
        end
      else
        int = int % values[i] # Equal to the remainder
      end
    end
  end

  roman_num

end

puts numerals_subtraction(494)
puts numerals_subtraction(400)
puts numerals_subtraction(900)