Largest 3-Same-Digit Number in String.cpp

class Solution {
public:
    string largestGoodInteger(string num) {
        string ans = "";
        for(int i=1; i<num.size()-1; i++) {
            if(num[i-1] == num[i] && num[i] == num[i+1]) {
				string temp = {num[i-1], num[i], num[i+1]};
                ans = max(ans, temp);
            }
        }
        return ans;    
    }
};