[LeetCode] #12 Integer to Roman

Given an integer, convert it to a roman numeral.

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

 将不同罗马字符和对应的数字做成字典，然后将依次转化。时间：55ms

代码如下：

class Solution {
public:
    string intToRoman(int num) {
        if (num < 1||num>3999)
            return "";
        string symbol[] = { "M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I" };
        int value[] = { 1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1 };
        string Roman;
        for (int i = 0; num != 0;i++){
            while (num >= value[i]){
                Roman += symbol[i];
                num -= value[i];
            }
        }
        return Roman;
    }
};