N2447 - 별 찍기 - 10

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.util.Scanner;

public class Main {
    private static final BufferedWriter BW = new BufferedWriter(new OutputStreamWriter(System.out));
    private static final Scanner SC = new Scanner(System.in);
    private static final StringBuffer SB = new StringBuffer("");

    public static void main(String[] args) throws IOException {
        int n = SC.nextInt();
        for(String s : devide(n)) SB.append(s).append("\n");
        BW.write(SB.toString());
        BW.close();
    }

    private static String[] devide(int n) {
        if(n==1) SB.append("*");
        if(n==3) return new String[]{"***", "* *", "***"};
        else return conquer(devide(n/3));
    }

    private static String[] conquer(String[] outer) {
        int tmp = 0;
        String[] inner = new String[outer.length];
        String[] result = new String[outer.length*3];
        for(int i=0; i<inner.length; i++) inner[i] = " ".repeat(outer.length);
        for(int i=0; i<outer.length; i++) result[tmp++] = outer[i].repeat(3);
        for(int i=0; i<outer.length; i++) result[tmp++] = outer[i] + inner[i] + outer[i];
        for(int i=0; i<outer.length; i++) result[tmp++] = outer[i].repeat(3);
        return result;
    }
}