题解 | #箭形图案#

import java.util.Scanner;
public class Main {
    
    public static void main(String[] args) {
        
        Scanner sc = new Scanner(System.in);
        while(sc.hasNextInt()) {
            int num = sc.nextInt();
            for(int i = 1 ; i <= num + 1 ; i++) {
                for(int k = i ; k <= num ; k++) {    //输出空格
                    System.out.print("  ");
                }
                for(int j = 1 ; j <= i ; j++) {
                    System.out.print("*");
                }
                System.out.println();
            }
            for(int i = 1 ; i <= num ; i++) {
                for(int k = 1 ; k <= i ; k++) {
                    System.out.print("  ");
                }
                for(int j = num ; j >= i ; j--) {
                    System.out.print("*");
                }
                System.out.println();
            }
        }
    }
}