12_intToRoman.cpp

class Solution {
public:
    string intToRoman(int num) {
        string res;
        while(num>=1000){
            res+='M';
            num-=1000;
        }
        if(num>=900){
            res+="CM";
            num-=900;
        }if(num>=500){
            res+='D';
            num-=500;
        }else if(num>=400){
            res+="CD";
            num-=400;
        }
        while(num>=100){
            res+='C';
            num-=100;
        }
        if(num>=90){
            res+="XC";
            num-=90;
        }if(num>=50){
            res+='L';
            num-=50;
        }else if(num>=40){
            res+="XL";
            num-=40;
        }
        while(num>=10){
            res+='X';
            num-=10;
        }
        if(num>=9){
            res+="IX";
            num-=9;
        }if(num>=5){
            res+='V';
            num-=5;
        }else if(num>=4){
            res+="IV";
            num-=4;
        }
        while(num>0){
            res+='I';
            num--;
        }
        return res;
    }
};