https://school.programmers.co.kr/learn/courses/30/lessons/12939
#include <string>
#include <vector>
#include <sstream>
#include <algorithm>
using namespace std;
string solution(string s) {
string answer = "";
vector<int> v;
stringstream ss(s);
string buf;
while(getline(ss, buf, ' ')){
v.push_back(stoi(buf));
}
sort(v.begin(), v.end());
answer += to_string(v[0]);
answer += " ";
answer += to_string(v[v.size()-1]);
return answer;
}