考虑一下此附加的伪代码和提示（其中一些是有效的Python，一些不是有效的，但有注释）。
def numberOfNumeral(n): """ Return the number represented by the single numeral """ # e.g. "v" -> 5, "i" -> 5 (and handle v/V cases, etc.)# avoid "string" as a variable name# I chose "ns" for "numerals" (which might be better),# but I'm also a bit terse .. anyway, name variables for what they represents.ns = str(input("Enter a roman numeral"))while ns: firstNum = numberOfNumeral(ns[0]) # This makes secondValue = -1 when there is only one numeral left # so firstNum is always "at least" secondNum when len(ns) == 1. secondNum = numberOfNumeral(ns[1]) if len(ns) > 1 else -1 if firstNum is at least secondNum: # Add firstNum to total. # Remove the character - so that the loop state advances. # If we don't don't his, as in the original, it will never end. # Here we use "slice notation". ns = ns[1:] else: # Add the difference, secondNum - firstNum, to total. # Remove both characters - again, so we advance state. ns = ns[2:]
