第八周作业

1.完善menu注册功能,抽奖,看小故事等功能

package a;

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

	public class sss {

	    
	    public static void main(String[] args) {
	        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:
	            cj();
	            break;
	        case 4:
	            storyn();
	            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("lxy") && upwd.equals("123")) {
	            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");
	        }

	    }
	    public static void zc(){
	            Scanner input = new Scanner(System.in);
	            System.out.println("======注册页面======");
	            System.out.println("请输入用户名");
	            String uname = input.next();
	            System.out.println("输入密码");
	            String upwd = input.next();
	            System.out.println("======返回登录页面=====");
	            login();
	    }
	    public static void storyn(){
	        Scanner input = new Scanner(System.in);
	        System.out.println("输入故事序号1，2，3，4，5");
	        int i = input.nextInt();
	        switch (i) {
	        case 1:
	            System.out.println("后羿射日");
	            break;
	        case 2:
	            System.out.println("女娲补天");
	            break;
	        case 3:
	            System.out.println("大禹治水");
	            break;
	        case 4:
	            System.out.println("大闹天宫");
	            break;
	        case 5:
	            System.out.println("小红帽");
	            break;
	        }
	        returnMain();
	    }
	    public static void cj(){
	          Scanner input = new Scanner(System.in);
	            Random r=new Random();
	            int x=r.nextInt(10);
	            System.out.println("随机数是"+x);
	            System.out.println("请输入四位会员卡号");
	            int u = input.nextInt();
	            if(x==u/10%10) {
	                System.out.println("是幸运会员!");
	            }else {
	                System.out.println("不是幸运会员");
	            }
	            returnMain();
	    }
	     private static void tc() {
	            System.out.println("是否退出系统?Y/N");
	            Scanner input = new Scanner(System.in);
	            if (input.next().equalsIgnoreCase("Y")) {
	                System.out.println("=====退出系统成功====");
	            }else{
	                mainMenu();
	                
	            }
	        }

	}

　　

2.编写一个方法，求整数n的阶乘，例如5的阶乘是1*2*3*4*5。 [必做题]

package a;


public class sss {
        public static int jc(int a){
            int sum=1;
            for (int i = 1; i <=a; i++) {
                sum*=a;
                
                
            }
            return sum;
        }
        public static void main(String[] args) {
            System.out.println(jc(6));
        }
}

　　

3.编写一个方法，判断该年份是平年还是闰年。[必做题]

package a;


public class sss {
    public static void main(String[] args) {
        near(2020);
    }
        public static void near(int y){
             if (y % 4 == 0 && y % 100 != 0 || y % 400 == 0) {
                    System.out.println(y + "年是闰年");
                } else {
                    System.out.println(y + "年不是闰年");
                }
        }

}