https://programmers.co.kr/learn/courses/30/lessons/12899
class Solution {
public String solution(int n) {
String answer = "";
while(true) {
int remain = n%3;
n = n/3;
if(remain == 0) {
answer = "4" + answer;
n--;
} else {
answer = remain + answer;
}
if(n==0) {
break;
}
}
return answer;
}
}