作业

作业1:完善menu注册功能,抽奖,看小故事等功能

package ww;
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:
            login();
            break;
        case 2:
            zc();
            break;
        case 3:
            cj();
            break;
        case 4:
            story();
            break;
        case 5:
            tc();
            break;

        }
    }

    public static void tc() {
        System.out.println("谢谢使用");

    }

    public static void story() {
        Scanner input = new Scanner(System.in);
        System.out.println("请选择想看的故事");
        System.out.println("1.故事1");
        System.out.println("2.故事2");
        System.out.println("3.故事3");
        int a = input.nextInt();
        switch (a) {
        case 1:
            System.out.println(" 故事一");
            break;
        case 2:
            System.out.println("故事二");
            break;
        case 3:
            System.out.println("故事三");
            break;

        }
        returnMain();
    }

    private static void cj() {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入四位会员卡号");
        int x = input.nextInt();
        Random r = new Random();
        int a = r.nextInt(10);
        if (x / 100 % 10 == a) {
            System.out.println("恭喜你中奖啦");
        } else {
            System.out.println("谢谢参与");
        }
        returnMain();
    }

    private 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 mima = input.next();
        System.out.println("注册成功");
        returnMain();
    }

    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("123")) {
            System.out.println("登录成功");
        } else {
            System.out.println("登录失败");
        }
        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1*2*3*4*5。 [必做题]

package ww;

public class dsa {
     public static int jc(int a) {
            int x = 1;
            for (int i = 1; i <= a; i++) {
                x *= i;
            }
            return x;
        }

        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 ww;

public class dsa {
    public static void main(String[] args) {
        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");
        }

    }
}