integer to roman leetcode c++实现

Given an integer, convert it to a roman numeral.

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

将整数用罗马数字表示。

思路分析：　　

{"","I","II","III","IV","V","VI","VII","VIII","IX"},
{"","X","XX","XXX","XL","L","LX","LXX","LXXX","XC"},
{"","C","CC","CCC","CD","D","DC","DCC","DCCC","CM"},
{"","M","MM","MMM"}

　　　　首先从输入的整数开始，（1）取其个位上的数值，判定后得到一个字符串（这个字符串也应该位于罗马数字的最右边，所以再用一个栈来解决）

　　　　　　　　　　　　　　　（2）然后将整数除以10（轮到十位上的数值了），再去执行（1）

代码如下：

　　　　

#include<stack>
class Solution {
public:
    string intToRoman(int num) {
        vector<vector<string>> data={
            {"","I","II","III","IV","V","VI","VII","VIII","IX"},
            {"","X","XX","XXX","XL","L","LX","LXX","LXXX","XC"},
            {"","C","CC","CCC","CD","D","DC","DCC","DCCC","CM"},
            {"","M","MM","MMM"}
        };
        stack<string> sta;
        int i=0;
        string res="",result="";
        while(num!=0){
            int remain=num%10;
            res=data[i][remain];
            sta.push(res);
            ++i;
            num/=10;
        }
        while(!sta.empty()){
            result+=sta.top();
            sta.pop();
        }
        return result;
    }
};