leetcode12.整数转罗马数字

Python3：

class Solution:
    def intToRoman(self, num: int) -> str:
        # 初始化字典
        val={
            1000:"M",
            900:"CM",
            500:"D",
            400:"CD",
            100:"C",
            90:"XC",
            50:"L",
            40:"XL",
            10:"X",
            9:"IX",
            5:"V",
            4:"IV",
            1:"I"
        }
        # 存储结果
        ans=""
        # 遍历字典
        for key,value in val.items():
            while key<=num:
                ans+=value
                num-=key
        # 返回结果
        return ans

C++：

// 初始化pair结构
const pair<int,string> val[]={
    {1000,"M"},
    {900,"CM"},
    {500,"D"},
    {400,"CD"},
    {100,"C"},
    {90,"XC"},
    {50,"L"},
    {40,"XL"},
    {10,"X"},
    {9,"IX"},
    {5,"V"},
    {4,"IV"},
    {1,"I"}
};
class Solution {
public:
    string intToRoman(int num) {
        // 存储结果
        string ans="";
        // 遍历pair结构的val
        for(const auto va :val){
            // 从大到小存储输出
            while(va.first<=num){
                ans+=va.second;
                num-=va.first;
            }
        }
        // 返回结果
        return ans;
    }
};