Java第十周作业

1编写一个方法，实现冒泡排序法（由小到大），并调用该方法

import java.util.Scanner;

public class test {
    public static void menthod() {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入5位数组");
        int x[] = new int[5];
        for (int i = 0; i < x.length; i++) {
            x[i] = input.nextInt();
        }
        for (int i = 0; i < x.length - 1; i++) {
            for (int j = 0; j < x.length - 1; j++) {
                if (x[j] > x[j + 1]) {
                    int t = x[j];
                    x[j] = x[j + 1];
                    x[j + 1] = t;
                }
            }
        }
        for (int i : x) {
            System.out.println(i);
        }
    }

    public static void main(String[] args) {
        menthod();
    }

}

 

 2编写一个方法，求n的阶乘

public class test {
    public static int j(int n) {
        int sum = 1;
        for (int i = 1; i <= n; i++) {
            sum = sum * i;
        }
        return sum;
    }

    public static void main(String[] args) {
        System.out.println("阶乘为" + j(6));
    }
}

 

 3 编写一个方法，判断该年份是平年还是闰年。

import java.util.Scanner;

public class test {
    public static void menthod() {
        Scanner input = new Scanner(System.in);
        System.out.println("输入年份");
        int year = input.nextInt();
        if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {
            System.out.println("是闰年");
        } else {
            System.out.println("是平年");
        }
    }

    public static void main(String[] args) {
        menthod();

    }
}

 

  4.课堂没完成的menu菜单，实现幸运抽奖功能

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

public class test {
    public static void mainMenu() {
        Scanner input = new Scanner(System.in);
        System.out.println("欢迎使用本系统");
        System.out.println("1.登录");
        System.out.println("2.注册");
        System.out.println("3.幸运抽奖");
        System.out.println("4.退出");
        System.out.println("请选择");
        int x = input.nextInt();
        switch (x) {
        case 1:
            login();
            break;
        case 2:
            register();
            break;
        case 3:
            luckdraw();
          break;
        }

    }

    public static void luckdraw() {
     
        Scanner input = new Scanner(System.in);
        System.out.println("输入四位会员卡号");
        Random r = new Random();
        int y = r.nextInt(10);
        int num = input.nextInt();
        while (num < 1000 || num > 10000) {
            System.out.println("输入有误,重新输入");
            num = input.nextInt();
            if (num >= 1000 && num < 10000) {
                break;
            }
        }
        int b = num % 1000 / 100;
        if (b == y) {
            System.out.println("幸运会员");
        } else {
            System.out.println("不是幸运会员");
        }

        returnMain();
    }

    public static void returnMain() {
        Scanner input = new Scanner(System.in);
        System.out.println("是否返回主菜单？");
        if (input.next().equalsIgnoreCase("Y"))
            mainMenu();
        else
            System.out.println("谢谢使用");
    }

    public static void register() {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入要注册的用户名");
        String uname = input.next();
        System.out.println("输入注册密码");
        String pwd = input.next();
        System.out.println("注册成功");
        returnMain();

    }

    public 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 pwd = input.next();
        if (uname.equals("admin") && pwd.equals("admin")) {
            System.out.println("成功");
        } else {
            System.out.println("失败");
        }
        returnMain();
    }

    public static void main(String[] args) {
        mainMenu();
    }
}