def decToRoman(num,s,decs,romans):
	"""
	  convert a Decimal number to Roman numeral recursively
	  num: the decimal number
	  s: the roman numerial string
	  decs: current list of decimal denomination
	  romans: current list of roman denomination
	"""
	if decs:
	  if (num < decs[0]):
	    # deal with the rest denomination
	    return decToRoman(num,s,decs[1:],romans[1:])		  
	  else:
	    # deduce this denomation till num<desc[0]
	    return decToRoman(num-decs[0],s+romans[0],decs,romans)	  
	else:
	  # we run out of denomination, we are done 
	  return s

	  convert a Decimal number to Roman numeral recursively
	  num: the decimal number
	  s: the roman numerial string
	  decs: current list of decimal denomination
	  romans: current list of roman denomination
	
recipes/Python/415384_Decimal_to_Roman_numerals/recipe-415384.py