최대값과 최소값

import java.util.*;
 
class Solution {
    public String solution(String s) {
        String answer = " ";
        String[] sArr = s.split(" "); //문자열 쪼개기
        List<Integer> list = new ArrayList();
        String isMinus = "";
        
        for(int i =0; i<sArr.length; i++){
            if(sArr[i].equals("-")){
                isMinus+=sArr[i]; //음수일 시 판별
            }else{
                isMinus += sArr[i];
                list.add(Integer.parseInt(isMinus));
                isMinus = "";
            }
        }
        Collections.sort(list);
        StringBuilder sb = new StringBuilder();
        sb.append(list.get(0));
        sb.append(" ");
        sb.append(list.get(list.size()-1));
        answer = sb.toString();    
        return answer;
    }
}