[BOJ 2446] 별 찍기 - 12

import java.util.Arrays;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int num = sc.nextInt();
        int length = 2*num-1;
        int blank = 0;
        int star = 0;

        for(int i=0;i<length;i++) {
            blank = i<num? i:length-(i+1);
            star = i<num? length-i*2:((i-num+1)*2)+1;

                for(int j=0;j<length;j++) {
                    if(star==0) break;

                    while(blank!=0) {
                        System.out.print(" ");
                        blank--;
                    }

                    while(star!=0) {
                        System.out.print("*");
                        star--;
                    }
                }
                System.out.println();
        }
    }
}