第八周作业

1. :完善menu注册功能,抽奖,看小故事等功能

package yukikaze;
import java.util.Random;
import java.util.Scanner;
public class mhm {

    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.抽奖.");
        System.out.println("4.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:
            denglu();
            break;
        case 2:
            zhuce();
            break;
        case 3:
            choujiang();
            break;
        case 4:
            xiaogushi();
            break;
        case 5:
            tuichu();
            break;
            
        }
    }

    public static void denglu() {
        // 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("123")) {
            System.out.println("登录成功");
        } else {
            System.out.println("登录失败");
        }
        returnMain();
    
    }
    public static void zhuce() {
        Scanner input = new Scanner(System.in);
        System.out.println("用户名：");
        String uname = input.next();
        System.out.println("密码：");
        String upwd = input.next();
        if(uname.equals(null) || upwd.equals(null) ) {
            System.out.println("注册失败");
        }else {
            System.out.println("注册成功");
        }
        returnMain();
    }
    public static void choujiang() {
        System.out.println("1.转盘抽奖");
        System.out.println("2.会员号抽奖");
        Scanner input = new Scanner(System.in);
        int x=input.nextInt();
        switch(x) {
        case 1:
            zp();
            break;
        case 2:
            sz();
            break;
        }
    }
    public static void zp() {
        Scanner input = new Scanner(System.in);
        System.out.println("转盘：");
        Random r=new Random();
        int hy=r.nextInt(10);
        System.out.println(hy);
        System.out.println("转出4位数");
        int num=input.nextInt();
        if(num/10%10==hy) {
            System.out.println("中奖");
        }else {
            System.out.println("未中奖");
        }
        returnMain();
    }
    public static void sz() {
        Scanner input = new Scanner(System.in);
        System.out.println("会员号抽奖");
        Random r=new Random();
        int hy=r.nextInt(10);
        System.out.println("请输入四位会员数");
        int num=input.nextInt();
        if(num/100%10==hy) {
            System.out.println("中奖");
        }else {
            System.out.println("未中奖");
        }
        returnMain();
    }
    public static void xiaogushi() {
        System.out.println("选故事");
        System.out.println("1.丑小鸭");
        System.out.println("2.小红帽");
        System.out.println("3.狼来了");
        returnMain();
    }
    public static void tuichu() {
        System.out.println("是否退出系统Y/N");
        Scanner input = new Scanner(System.in);
        String a = input.next();
        if(a.equalsIgnoreCase("y")) {
            System.out.println("退出系统成功");
        }else {
            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");
        }
  }

}

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。

package yukikaze;
import java.util.Scanner;
public class mhm {
    private static int jc(int x)
    {
        int sum=1;
        for (int i=x; i>0;i--)
        {
            sum*=i;
        }
        return sum;
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
         System.out.println("输入一个数字");
            Scanner a=new Scanner(System.in);
            System.out.println("阶乘为" + jc(a.nextInt()));
        }
}

3．.编写一个方法，判断该年份是平年还是闰年

package yukikaze;
import java.util.Scanner;
public class mhm {
    
    public static void main(String[] args) {
        // TODO Auto-generated method stub
           jcsf p = new jcsf();
            p.nianfen(2020);
        }
        public void nianfen(int year) {
            int a;
            a=year;
            if(a%4==0 && a%100!=0 || a%400==0) {
                System.out.println(a+"是闰年");
            }else {
                System.out.println(a+"不是闰年");
            }
        }
    }