题解 | #箭形图案#

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        while(scan.hasNextInt()) {
            int n = scan.nextInt();
            //上层的图形
            int x = n;
            for(int i = 1; i <= n; i++) {
                for(int j = 2 * x; j >= 1; j--) {
                    System.out.print(" ");
                }
                x--;
                for(int j = 1; j <= i; j++) {
                    System.out.print("*");
                }
                System.out.println();
            }
            //最长的那条线
            for(int i = 1; i <= n + 1; i++) {
                System.out.print("*");
            }
            System.out.println();
            //下层的部分
            for(int i = 1; i <= n; i++) {
                for(int j = 1; j <= 2 * i; j++) {
                    System.out.print(" ");
                }
                for(int j = n; j >= i; j--) {
                    System.out.print("*");
                }
                System.out.println();
            }
        }
    }
}