12 Integer to Roman

纯模拟

class Solution(object):
    def intToRoman(self, num):
        """
        :type num: int
        :rtype: str
        """
        d = {
                1:"I",
                4:"IV",
                5:"V",
                9:"IX",
                10:"X",
                40:"XL",
                50:"L",
                90:"XC",
                100:"C",
                400:"CD",
                500:"D",
                900:"CM",
                1000:"M"
        }
        ans = ""
        while num:
            for i in [1000,900,500,400,100,90,50,40,10,9,5,4,1]:
                if i <= num:
                    j = i
                    break
            num -= j
            ans += d[j]
        return ans