java第八周課後作業

1.系統小練習

package homework;

import java.util.Random;
import java.util.Scanner;

public class Menu {

	public static void main(String[] args) {
		mainMenu();
	}

	public static void mainMenu() {
		Scanner input = new Scanner(System.in);
		System.out.println("****************");
		System.out.println("   1. 登入");
		System.out.println("   2. 注冊");
		System.out.println("   3.幸運抽獎");
		System.out.println("   4.看小故事");
		System.out.println("   5.退出系統");
		System.out.println("****************");
		System.out.print("請選擇:");
		int i = input.nextInt();
		switch (i) {
		case 1:
			login();
			break;
		case 2:
			register();
			break;
		case 3:
			luck();
			break;
		case 4:
			story();
			break;
		case 5:
			exit();
			break;
		default:
			System.out.println("該系統暫未開放其它功能！");
			break;
		}
	}

	private static void login() {
		// TODO Auto-generated method stub
		Scanner input = new Scanner(System.in);
		System.out.print("請輸入您的使用者名：");
		String uname = input.next();
		System.out.print("請輸入您的密碼：");
		String upwd = input.next();
		if (uname.equals("zs") && upwd.equals("123")) {
			System.out.println("登入成功!");
		} else {
			System.out.println("登入失敗");
		}
		returnMain();

	}

	public static void returnMain() {
		System.out.println("是否傳回主菜單?Y/N");
		Scanner input = new Scanner(System.in);
		if (input.next().equalsIgnoreCase("Y")) {
			mainMenu();
		} else {
			System.out.println("謝謝使用");
		}

	}

	public static void register() {
		Scanner input = new Scanner(System.in);
		System.out.print("請輸入您的使用者名:");
		String uname = input.next();
		System.out.print("請輸入您的密碼：");
		String upwd = input.next();
		System.out.println("您的賬号已注冊成功！！！");
		returnMain();
	}

	public static void luck() {
		System.out.println("**************************************歡迎來到幸運抽獎界面！*************************************");
		System.out.println(" *******規則為：如果您輸入的四位會員卡号的百位等于系統随機數,您将成為我們的幸運會員,否則不是*******");
		Scanner input = new Scanner(System.in);
		int temp = 0;
		for (int i = 0;; i++) {
			System.out.print("請您輸入四位的會員卡号：");
			int vipcard = input.nextInt();
			int bai = vipcard % 1000 / 100;
			temp = bai;
			if (vipcard < 999 || vipcard > 9999) {
				System.out.println("您的會員卡号錯誤,請您重新輸入！");
			} else {
				break;
			}
		}
		Random r = new Random();
		int num = r.nextInt(9);
		System.out.println("系統生成的百位随機數為：" + num);
		if (num == temp) {
			System.out.println("恭喜您,成為我們的幸運會員！");
		} else {
			System.out.println("很遺憾,謝謝您的參與！");
		}
		returnMain();
	}

	public static void story() {
		System.out.println("歡迎您來到小故事界面,請您輸入相應的數字(1-3)進行觀看！");
		for (int i = 0;; i++) {
			Scanner input = new Scanner(System.in);
			int num = input.nextInt();
			switch (num) {
			case 1:
				System.out.println("男兒事業多，何必學讀書 —— 宋 · 張耒《阿幾》");
				break;
			case 2:
				System.out.println("阿爺無大兒，木蘭無長兄，願為市鞍馬，從此替爺征 —— 南北朝 · 佚名《木蘭詩 / 木蘭辭》");
				break;
			case 3:
				System.out.println("大兒荷锸去疏麻，小兒提筐來采茶，翁自決水灌秧芽 —— 宋 · 艾性夫《田家詞》");
				break;
			default:
				System.out.println("您的輸入有錯,請重新輸入！");
			}
			break;
		}
		returnMain();
	}

	public static void exit() {
		System.out.println("是否退出該系統?Y/N");
		Scanner input = new Scanner(System.in);
		if (input.next().equalsIgnoreCase("N")) {
			mainMenu();
		} else {
			System.out.println("您已退出我們的系統,謝謝使用!");
		}

	}

}
      

2.編寫一個方法，求整數n的階乘 例如5的階乘是5*4*3*2*1

public static int Jc(int n) {
		int cj=1;
		for (int i = 1; i <= n; i++) {
			cj*=i;
		}
		return cj;
	}
	public static void main(String[] args) {
		System.out.println(Jc(5));
	}
      

　　

3.編寫一個方法 判斷該年份是平年還是閏年

public static void Year(int n) {
		if (n % 4 == 0 && n % 100 != 0 || n % 400 == 0) {
			System.out.println(n + "是閏年");
		} else {
			System.out.println(n + "是平年");
		}
	}

	public static void main(String[] args) {
		Year y = new Year();
		Year(2020);
	}