[BOJ] 2447. 별 찍기 - 10

import java.util.Scanner;

public class Main {
	static Scanner sc=new Scanner(System.in);
	static int N=sc.nextInt();
//	static char arr[][]=new char [N][N];
	static StringBuilder sb=new StringBuilder();
	public static void main(String[] args) {
		fill();
		go(0,0,N);
		System.out.println(sb);
	}
	
	public static void fill() {
		for (int i = 0; i < N; i++) {
			for (int j = 0; j < N; j++) {
				sb.append('*');
			}
			sb.append('\n');
		}	
	}
	
	public static void go(int x,int y,int n) {
		if(n==1) return;
		for (int i = x+n/3; i < x+2*n/3; i++) {
			for (int j = y+n/3; j < y+2*n/3; j++) {
				sb.setCharAt(((N+1)*i)+j,' ');
			}
		}
		
		for (int i = 0; i < 3; i++) {
			for (int j = 0; j < 3; j++) {
				go(x+i*n/3,y+j*n/3,n/3);
			}
		}
	}
}