题目：力扣（LeetCode）官网 - 全球极客挚爱的技术成长平台

直接按照题目模拟过程即可

public String intToRoman(int num) {
        int []a={1000,900,500,400,100,90,50,40,10,9,5,4,1};
        String []b={"M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"};
        String sum = "";
        for(int i=0;i<a.length;i++)
        {
            while(num>=a[i])
            {
                sum=sum+b[i];
                num=num-a[i];
            }
        }
        return sum;
    }