최대값과 최소값

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;

class Solution {
    public String solution(String s) {
        String answer = "";
        
        ArrayList<Integer> list = new ArrayList<>();
        String temp = "";
        for(int i = 0; i < s.length(); i++){
            if(s.charAt(i) == ' '){
                list.add(Integer.parseInt(temp));
                temp = "";
            } else {
                temp += String.valueOf(s.charAt(i));
            }

            if(i == s.length() - 1){
                list.add(Integer.parseInt(temp));
            }
        }


        Collections.sort(list);

        int min = list.get(0);
        int max = list.get(list.size() - 1);
        answer += min + " " + max;

        return answer;
    }
}