[Programmers/C++] 가장 큰 수

#include <algorithm>
#include <string>
#include <vector>
#include <iostream>
 
using namespace std;
 
bool compare(string &a, string &b)
{
    cout << a << b << endl;
    if (b + a < a + b)
        return true;
    return false;
}
 
string solution(vector<int> numbers) {
    string answer = "";
 
    vector<string> strings;
 
    for (int i : numbers)
        strings.push_back(to_string(i));
    
    sort(strings.begin(), strings.end(), compare);
 
    for (int i = 0; i< strings.size(); i++){
        answer += strings[i];
    }
 
    if (answer[0] == '0')
        answer = "0";
 
    return answer;
}