[Level 1] 3진법 뒤집기

class Solution {
    public int solution(int n) {
        int answer = 0;
        StringBuilder sb = new StringBuilder();
        
        while(n>0) {
            sb.append(String.valueOf(n%3));
            n /= 3;
        }
        
        String s = sb.toString();
        for(int i=0; i<s.length(); i++) {
            answer += (s.charAt(i)-'0')*Math.pow(3, s.length()-1-i);
        }
        
        return answer;
    }
}