第八周作业

1.完善menu注册功能,抽奖,看小故事等功能

package chap;

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("1.登录");
        System.out.println("2.注册");
        System.out.println("3.幸运抽奖");
        System.out.println("4.看小故事");
        System.out.println("5.退出系统");
        System.out.println("请选择");
        int n=input.nextInt();
        switch(n){
        case 1:
            dl();
            break;
        case 2:
            zc();
            break;
        case 3:
            cj();
            break;
        case 4:
            gs();
            break;
        case 5:
            tc();
            break;    
        }
    }
    
    public static void dl(){
        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 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 pwd=input.next();
        System.out.println("注册成功");
        returnmain();
    }
    
    public static void cj(){
        Scanner input=new Scanner(System.in);
        System.out.println("请输入四位会员卡号：");
        int i=input.nextInt();
        Random r=new Random();
        int x=r.nextInt(10);
        if(i/100%10==x){
            System.out.println("中奖啦");
        }else{
            System.out.println("谢谢参与");
        }
        returnmain();
    }
    
    public static void gs(){
        Scanner input=new Scanner(System.in);
        System.out.println("请选择故事：");
        System.out.println("1.画龙点睛");
        System.out.println("2.画蛇添足");
        int i=input.nextInt();
        switch(i){
        case 1: 
            System.out.println("画龙不画眼睛，画眼睛龙会飞走");
            break;
        case 2:
            System.out.println("画蛇时为蛇添上脚");
            break;
        }
        returnmain();
    }
    
    public static void tc(){
        System.out.println("谢谢使用");
    }
    
    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。 [必做题]

package chap;

public class util {
    public static int jc(int x){
        int sum=1;
        for (int i = 1; i <= x; i++) {
            sum*=i;
        }
        return sum;
    }
    public static void main(String[]args){
        System.out.println(jc(5));
    }
}

3.编写一个方法，判断该年份是平年还是闰年。[必做题]

package chap;

public class util {
    public static void x(int year){
        if(year%4==0&&year%100!=0||year%400==0){
            System.out.println("是闰年");
        }else
            System.out.println("是平年");
    }
    public static void main(String[]args){
        x(2020);
    }
}