[프로그래머스] 정수 내림차순 배치하기

import java.util.*;
class Solution {
    public long solution(long n) {
        long answer = 0;
        StringBuilder sb = new StringBuilder();
        
        String[] list = String.valueOf(n).split("");
        Arrays.sort(list);
        
        for(String s: list){
            sb.append(s);
        }
        
        answer = Long.parseLong(sb.reverse().toString());
        
        
        return answer;
    }
}