第八周作业

1:完善menu注册功能,抽奖,看小故事等功能

import java.util.*;
public class R{
    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.看故事,");
        System.out.println("5.退出本系统");
        System.out.println("请选择");
        int i = input.nextInt();
        switch (i) {
        case 1:
            login();
            break;
        case 2:
            register();
            break;
        case 3:
            choujiang();
            break;
        case 4:
            kgs();
            break;
        case 5:
            break;
        
        }
    }

    private static void login() {
        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("111")) {
            System.out.println("登录成功");
        } else {
            System.out.println("登录失败");
        }
        returnMain();
    
    }
    
    public static void register(){
        System.out.println("请输入用户名:");
        Scanner input= new Scanner(System.in);
        String line=input.nextLine();
        System.out.println("请输入密码");
        int a =input.nextInt();
        login();
        
    }
    
    private static void choujiang(){
        Random r=new Random();
        int x=r.nextInt(10);
        System.out.println("请输入4位号码:");
        Scanner input=new Scanner(System.in);
        int i= input.nextInt();
        if(x==i%1000/100){
            System.out.println("恭喜您中奖了!");
        }else{
            System.out.println("很遗憾，您没有中奖");
        }
        returnMain();
    }
    
    private static void kgs(){
        System.out.println("格林童话");
        returnMain();
    }
    
    public static void returnMain(){
        System.out.println("是否返回主菜单?是（Y）/否（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]

import java.util.*;
public class R{
    public static void main(String[] args) {
        jiec();
    }
    public static void jiec(){
        Scanner input =new Scanner(System.in);
        int sum=1;
        System.out.println("请输入一个整数");
        int a=input.nextInt();
        for (int i = 1; i <= a; i++) {
            sum*=i;
             
        }
         System.out.println("阶乘为"+sum);
    }
}

3.编写一个方法，判断该年份是平年还是闰年。[必做题]

import java.util.*;
public class R{
    public static void Text(int year) {
        if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {
            System.out.println(year + "是闰年");
        } else {
            System.out.println(year + "不是闰年");
        }
    }
    public static void main(String[] args) {
        System.out.println("请输入年份");
        Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        Text(n);
 
    }
}