第九次作业

1.编写一个方法，实现冒泡排序（由小到大），并调用该方法

package ZF;

import java.util.Scanner;

public class Zf1 {
    public static void maps() {
        Scanner input=new Scanner(System.in);
        System.out.println("请输入五个数");
        int a[]=new int[5];
        for (int i = 0; i < a.length; i++) {
            a[i]=input.nextInt();
        }
        for (int i = 0; i < a.length-1; i++) {
            for (int j = 0; j < a.length-1-i; j++) {
                if(a[j]>a[j+1]) {
                int max=a[j];
                a[j]=a[j+1];
                a[j+1]=max;
                }
            }
            
        }
        System.out.println("排序后");
        for (int i = 0; i < a.length; i++){
            System.out.println(a[i]);
        }
    }

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

    }

}

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 ZF;

public class Zf2 {
    public static int maps(int x) {
        int sum=1;
        for (int i = 1; i <= x; i++) {
            sum=sum*i;
        }
        return sum;
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println(maps(5));

    }

}

3.编写一个方法，判断该年份是平年还是闰年。[必做题]

package ZF;

import java.util.Scanner;

public class Zf3 {
    public static void maps() {
        System.out.println("请输入年份");
        Scanner input=new Scanner(System.in);
        int year=input.nextInt();
        if(year%4==0&&year%100!=0||year%400==0)
            System.out.println("闰年");
    }

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

    }

}

4.课堂没完成的menu菜单，实现幸运抽奖功能

package ZF;

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

public class Zf4 {


    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 i=input.nextInt();
        switch(i) {
        case 1:
            d();
            break;
        case 2:
            z();
            break;
        case 3:
            x();
            break;
        }
    }
    public static void returnMain() {
        Scanner input=new Scanner(System.in);
        System.out.println("是否返回主菜单？Y/N");
        if(input.next().equalsIgnoreCase("Y"))
            mainMenu();
        else
            System.out.println("谢谢使用");
        
    }
    public static void d() {
        Scanner input=new Scanner(System.in);
        System.out.println("输入用户名");
        String name=input.next();
        System.out.println("输入密码");
        String mima=input.next();
        if(name.equals("abcde")&&mima.equals("abcde"))
            System.out.println("成功");
        else
            System.out.println("失败");
        returnMain();
    }
    public static void z() {
        Scanner input=new Scanner(System.in);
        System.out.println("输入用户名");
        String name=input.next();
        System.out.println("输入密码");
        String mima=input.next();
        System.out.println("注册成功");
        returnMain();
    }
    public static void x() {
        Scanner input=new Scanner(System.in);
        System.out.println("请输入四位会员卡号");
        int x=input.nextInt();
        int a=x/100%10;
        Random r=new Random();
        int b=r.nextInt(10);
        if(a==b) {
            System.out.println("该用户是幸运用户");
        }
            else
            {
                System.out.println("该用户不是是幸运用户");
        }
        returnMain();
    }
    
    

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

    }

}