roman_numerals.rb

### Ancient Roman Numerals

def to_roman(integer, numeral="")
  return numeral if integer == 0

  if 	integer/1000 >= 1
    numeral << 'M' * ( integer/1000 )
    remainder = integer % 1000
  elsif integer/500 >= 1
    numeral << 'D' * ( integer/500 )
    remainder = integer % 100
  elsif integer/100 >= 1
    numeral << 'C' * ( integer/100 )
    remainder = integer % 100
  elsif integer/50 >= 1
    numeral << 'L' * ( integer/50 )
    remainder = integer % 50
  elsif integer/10 >= 1
    numeral << 'X' * ( integer/10 )
    remainder = integer % 10
  elsif integer/5 >= 1
    numeral << 'V' * ( integer/5 )
    remainder = integer % 5
  else
    numeral << 'I' * ( integer )
    remainder = 0
  end

  to_roman(remainder,numeral)
end



### Modern Roman Numerals

def to_roman_modern(integer, numeral="")
  return numeral if integer == 0

  if 	integer/1000 >= 1
	numeral << 'M' * ( integer/1000 )
	remainder = integer%1000
  elsif integer/500 >= 1
	integer/900 == 1 ? numeral << 'CM' : numeral << 'D' * ( integer/500 )
	integer/900 == 1 ? remainder = integer%900 : remainder = integer%500
  elsif integer/100 >= 1
	integer/100 > 3 ? numeral << 'CD' : numeral << 'C' * ( integer/100 )
	remainder = integer%100
  elsif integer/50 >= 1
	integer/90 == 1 ? numeral << 'XC' : numeral << 'L' * ( integer/50 )
	integer/90 == 1 ? remainder = integer%90 : remainder = integer%50
  elsif integer/10 >= 1
	integer/10 > 3 ? numeral << 'XL' : numeral << 'X' * ( integer/10 )
	remainder = integer % 10
  elsif integer/5 >= 1
	integer/9 == 1 ? numeral << 'IX' : numeral << 'V' * ( integer/5 )
	integer/9 == 1 ? remainder = 0 : remainder = integer%5
  else
	integer > 3 ? numeral << 'IV' : numeral << 'I' * ( integer )
	remainder = 0
  end

  to_roman_modern(remainder,numeral)
end

puts to_roman_modern(49)