第八周作业

1:完善menu注册功能,抽奖,看小故事等功能

package nmz;

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

public class nn { 
    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("欢迎使用本系统！！！！！！");
        System.out.println("1.登入");
        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:
            register();
            break;
        case 3:
            luck();
            break;
        case 4:
            lookstory();
            break;
        case 5:
            off();
            break;
        default:
            break;
        }
    }
    
    
    private static void login() {
        Scanner input = new Scanner(System.in);
        System.out.println("输入用户名：");
        String youName = input.next();
        System.out.println("输入密码：");
        String password = input.next();
        if (youName.equals("nmz") && password.equals("3344")) {
            System.out.println("登录成功");
        }else {
            System.out.println("登录失败");
        }
        returnMain();
    }
    
    
    private static void register() {
        Scanner input = new Scanner(System.in);
        System.out.println("输入昵称：");
        String jName = input.next();
        System.out.println("输入密码：");
        String password = input.next();
        System.out.println("注册成功");
        returnMain();
    }
    
    
    private static void luck() {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入四位会员卡号：");
        int hy = input.nextInt();
        Random sj = new Random();
        int x = sj.nextInt(10);
        if (hy/100%10 == x) {
            System.out.println("恭喜您中奖了");
        }else {
            System.out.println("谢谢参与");
        }
        returnMain();
    }
    
    private static void lookstory() {
        Scanner input = new Scanner(System.in);
        System.out.println("请选择想看的故事");
        System.out.println("1.三体");
        System.out.println("2.天才在左，疯子在右");
        System.out.println("3.苏菲的世界");
        int s = input.nextInt();
        switch (s) {
        case 1:
            System.out.println("讲述了军方探寻外星文明的绝密计划取得了突破性的进展，地球人类文明和三体文明的信息交流等。");
            break;
        case 2:
            System.out.println("以访谈录的形式记载了精神病患者和心理障碍者等边缘人的独特的所思所想。");
            break;
        case 3:
            System.out.println("由14岁少女苏菲收到的一封神秘的信所展开的故事。");
            break;
        default:
            break;
        }
        returnMain();
    }
    
    public static void off() {
        System.out.println("成功退出系统");
    }
    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 nmz;

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


public class nn { 
    public static void main(String[] args) {
         // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("请输入一个数");
        int a = input.nextInt();
        int jc = 1;
        for (int i = 1; i <= a; i++) {
            jc *= i;
        }
        System.out.println("该数的阶乘为：" + jc);
    }

}

3.编写一个方法，判断该年份是平年还是闰年。[必做题]

package nmz;

public class nn { 
    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 + "年是闰年");
        } else {
            System.out.println(year + "年不是闰年");
        }

    }
}