Integer to Roman （罗马数字转换)

class Solution {
public:

string intToRoman(int num) {
string symbol[] = {"M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"};
int value[] = {1000,900,500,400,100,90,50,40,10,9,5,4,1};
string result ;
int tmp = 0;
for(int i =0;num!=0&&i<13;i++){
while(num >= value[i]) {
num -= value[i];
result += symbol[i];
}
}
return result;
}
};