4.24 第八周作业

1.完善menu的注册功能，抽奖以及讲小故事等功能。

package text;

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

public class Menu {

    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.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:
            raffle();
            break;
        case 4:
            story();
            break;
        case 5:
            exit();
            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("zs") && upwd.equals("123")) {
            System.out.println("登录成功");
        } else {
            System.out.println("登录失败");
        }
        returnMain();

    }

    private static void register() {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("设置用户名");
        String uname = input.next();
        System.out.println("设置密码");
        String upwd = input.next();
        if (uname.equals(null) || upwd.equals(null)) {
            System.out.println("注册成功");
        } else {
            System.out.println("注册失败");
        }
        returnMain();

    }

    // 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
    private static void raffle() {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入四位会员卡号:");
        int kahao = input.nextInt();
        Random r = new Random();
        int suiji = r.nextInt(10);
        if (kahao / 100 % 10 == suiji) {
            System.out.println("恭喜您是幸运会员！");
        } else {
            System.out.println("您不是幸运会员");
        }
        returnMain();
    }

    public static void story() {
        System.out.println("三只小猪");
        returnMain();
    }

    public static void exit() {
        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5*4*3*2*1.

package text;

import java.util.Scanner;

public class JieCheng {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        jc();
    }

    public static void jc() {
        Scanner input = new Scanner(System.in);
        int mul = 1;
        System.out.println("输入一个数:");
        int a = input.nextInt();
        for (int i = 1; i <= a; i++) {
            mul *= i;
        }
        System.out.println(a + "的阶乘为:" + mul);
    }

}

3.编写一个方法，判断该年份是平年还是闰年。[必做题]

package text;

import java.util.Scanner;

public class JieCheng {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        nianfen();
    }

    public static void nianfen() {
        Scanner input = new Scanner(System.in);
        System.out.println("输入一个年数:");
        int year = input.nextInt();
        if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {
            System.out.println("该年份为闰年");
        } else {
            System.out.println("该年份为平年");
        }
    }
}