第八周作业

package Wxte;
import java.util.Random;
import java.util.Scanner;

public class Mast {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		mainMenu();
    }
    public static void mainMenu() {
        Scanner input = new Scanner(System.in);
        System.out.println("1.登录");
        System.out.println("2.注册");
        System.out.println("3.幸运抽奖,输入四位会员卡号,如果百位等于系统随机数,就是星运会员.否则不是.");
        System.out.println("4.看小故事,");
        System.out.println("5.退出系统");
        System.out.println("请选择");
        int i = input.nextInt();
        switch (i) {
        case 1:
            login();
            break;
        case 2:
            zc();
            break;
        case 3:
            xycj();
            break;
        case 4:
            kxgs();
            break;
        case 5:
            tc();
            break;
        }
    }
    private static void login() {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入用户名");
        String uname = input.next();
        System.out.println("输入密码");
        String upwd = input.next();
        if (uname.equals("zs") && upwd.equals("234")) {
            System.out.println("登录成功");
        } else {
            System.out.println("登录失败");
        }
        returnMain();
    }
    
    public static void returnMain(){
        System.out.println("是否返回主菜单?Y/N");
        Scanner input = new Scanner(System.in);
        if (input.next().equalsIgnoreCase("Y")) {
            mainMenu();
        }else{
            System.out.println("谢谢使用");
        }
    }
    private static void zc() {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入用户名");
        String name = input.next();
        System.out.println("请输入密码");
        String mm = input.next();
        System.out.println("注册成功");
        returnMain();
    }
    private static void xycj() {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入四位会员卡号");
        int x = input.nextInt();
        Random r = new Random();
        int a = r.nextInt(10);
        if (x / 10 % 10 == a) {
            System.out.println("恭喜你中奖啦!");
        } else {
            System.out.println("谢谢参与");
        }
        returnMain();
    }
    private static void kxgs() {
        Scanner input = new Scanner(System.in);
        System.out.println("请选择要看的故事：");
        System.out.println("1.丑小鸭");
        System.out.println("2.青蛙王子");
        int m = input.nextInt();
        switch(m) {
        case 1:
            System.out.println("丑小鸭");
            break;
        case 2:
            System.out.println("青蛙王子");
            break;
            returnMain();
        }
        private static void tc() {
            System.out.println("谢谢使用");
	

	}}

　　

package Wxte;
import java.util.Scanner;

public class Person {
	  
    public static int Factorial(int x) {
        int sum = 1;
        for (int a = 1; a <= x; a++) {
            sum *= a;
        }
        return sum;
    }
    
    public static void main(String[] args) {
        System.out.println("请输入一个数字：");
        Scanner input = new Scanner(System.in);
        int i = input.nextInt();
        System.out.println(i + "的阶乘是：" + Factorial(i));
        
  
}
}

　　

package Wxte;
import java.util.Random;
import java.util.Scanner;

public class Mast {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
	       prn(2020);
	    }

	    public static void prn(int year) {
	        if (year%4==0&&year%100!=0||year%400==0) {
	            System.out.println(year + "闰年");
	        } else {
	            System.out.println(year + "年不是闰年");
	        }

	    }
	}