[leetcode] Integer to Roman @ Python

题目： https://oj.leetcode.com/problems/integer-to-roman/

Given an integer, convert it to a roman numeral.

Input is guaranteed to be within the range from 1 to 3999.

思路：不是很清楚。

代码：

class Solution:
    # @return a string
    def intToRoman(self, num):
        ints = [1000, 900, 500, 400, 100,   90,  50,  40,    10,   9,    5,   4,    1]
        roms = ['M',  'CM', 'D','CD','C',  'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I']
        res =''
        for i in range(len(ints)):
            while num >= ints[i]:
                num -= ints[i]
                res += roms[i]
        return res