2021-10-29

package Test01;

import java.util.Scanner;

public class demo {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		System.out.println("Please input a number:");
		int L = input.nextInt();
		// 打印菱形前一半
		for (int i = 1; i <= L; i++) {
			int r = L - i - 1; // 空格数
			int k = 1;
			int s = 1; // k和s都是辅助变量
			if (i <= L - 1) {
				while (k <= r) {
					System.out.print(" ");
					k++;
				}
				while (s <= i) {
					System.out.print(" " + "*");
					s++;
				}
				System.out.println();
			} else {
				while (k <= i) {
					System.out.print("*" + " ");
					k++;
				}
			}
		}
		System.out.println();
		// 打印菱形后一半
		for (int i = 1; i <= L - 1; i++) {
			int k = 1;
			int s = 1;
			while (s <= i - 1) {
				System.out.print(" ");
				s++;
			}
			while (k <= L - i) {
				System.out.print(" " + "*");
				k++;
			}
			System.out.println();
		}
	}
}