Given an integer, convert it to a roman numeral.

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

题意：将阿拉伯数字转换为罗马数字表示

思路：首先了解罗马数字的表示，然后就是从大到小找符合的数字了

class Solution {
public:
    string intToRoman(int num) {
        string ans = "";
        string dit[] = {"M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"};
        int val[] = {1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1};  

        for (int i = 0; num > 0; i++) {
            while (num >= val[i]) {
                num -= val[i];
                ans += dit[i];
            }
        } 

        return ans;
    }
};

Leetcode Integer to Roman