题目链接：https://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.

class Solution {public:    string intToRoman(int num) {        int n[] = {1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1};        string r[] = {"M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"};        string res="";        for(int i=0;num>0;num = num%n[i],i++) // 确定是哪个            for(int j=0,k=num/n[i];j