把阿拉伯数字转换成罗马数字

class Solution {
public:
    string intToRoman(int num) {
        int values[13]={1000,900,500,400,100,90,50,40,10,9,5,4,1};
        string numbers[13]={"M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"};
        string result="";
        for(int i=0;i<13;i++)
        {
            while(num>=values[i])
            {
                num -= values[i];
                result=result+numbers[i];
            }
        }
        return result;
    }
};