第八周作业

1.完善menu注册功能,抽奖,看小故事等功能

package number8;

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

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:输入四位会员号,如果百位等于系统随机数,是幸运会员.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:
            logon();
            break;
        case 3:
            lucky();
                    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("hx") && upwd.equals("666")) {
            System.out.println("登录成功");
        } else {
            System.out.println("登录失败");
        }
        returnMain();
        
    }

    private static void logon() {
        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();
        System.out.println("注册成功!");
        returnMain();
    }

    private static void lucky() {
        Scanner input = new Scanner(System.in);
        System.out.println("输入四位会员卡号：");
        int x = input.nextInt();
        Random r = new Random();
        int a = r.nextInt(10);
        System.out.println("随机数:"+a);
        if (x % 1000 / 100 == a) {
            System.out.println("恭喜你，幸运会员!");
        } else {
            System.out.println("很抱歉，你不是!");
        }
        returnMain();
    }
    
    private static void story() {
        Scanner input = new Scanner(System.in);
        System.out.println("选择小故事");
        System.out.println("1.烧水的故事");
        System.out.println("2.农夫的故事");
        int a = input.nextInt();
        switch (a) {
        case 1:
            System.out.println(
                    " 老师问：“有个人要烧壶开水，生火到一半时发现柴不够，他该怎么办？“。
"
                            + "有的同学说赶快去找，有的说去借，去买。
"
                            + "老师说：“为什么不把壶里的水倒掉一些呢？”。同学顿悟4");
            break;
        case 2:
            System.out.println(
                    "有人问农夫：“种了麦子了吗？”
"
                            + "农夫：“没，我担心天不下雨。”
"
                            + "那人又问：“那你种棉花没？”
"
                            + "农夫：“没，我担心虫子吃了棉花。”
"
                            + "那人再问：“那你种了什么？”
"
                            + "农夫：“什么也没种，我要确保安全。”
");
        }
        returnMain();
    }
    
    public static void exit() {
        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

package number8;

import java.util.Scanner;

public class z {
    
    public static int F(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("输入一个数：");
        Scanner input = new Scanner(System.in);
        int i = input.nextInt();
        System.out.println(i + "的阶乘是：" + F(i));
        
    }
}

 3.编写一个方法，判断该年份是平年还是闰年

package number8;

import java.util.Scanner;

public class z {

    public static void y(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();
        y(n);

    }
}