[프로그래머스][JAVA] 문자열 내 마음대로 정렬하기 (문자열)

import java.util.*;
 
class Solution {
    public String[] solution(String[] strings, int n) {
        
        ArrayList<String> arr = new ArrayList<>();
        for (int i = 0; i < strings.length; i++) {
            arr.add("" + strings[i].charAt(n) + strings[i]);
        }
        Collections.sort(arr);
        String[] answer = new String[strings.length];
        for (int i = 0; i < strings.length; i++) {
            answer[i] = arr.get(i).substring(1,arr.get(i).length());
        }
        
        return answer;
    }
}