[프로그래머스] [LV1] 문자열 내림차순으로 배치하기

📚 문자열 내림차순으로 배치하기

링크📎 : https://programmers.co.kr/learn/courses/30/lessons/12917

난이도 ⭐️

📖 문제

📝 내 풀이

import java.util.*;

class Solution {
    public String solution(String s) {
        String answer = "";
        ArrayList <Character> upperS = new ArrayList<Character>();
        ArrayList <Character> lowerS = new ArrayList<Character>();
        
        for(int i = 0; i < s.length(); i++){
            if(Character.isUpperCase(s.charAt(i))) upperS.add(s.charAt(i));
            else lowerS.add(s.charAt(i));
        }
        
        Collections.sort(upperS);
        Collections.reverse(upperS);
        
        Collections.sort(lowerS);
        Collections.reverse(lowerS);
        
        for(char i : lowerS)
            answer += i;
        for(char i : upperS)
            answer += i;
        
        return answer;
    }
}

끝-!