第十次作业

1、编写一个方法，实现冒泡排序（由小到大），并调用该方法

package mrb;

 

public class Asd {

   /**

     * @param args

     */

    public static void main(String[] args) {

        // TODO Auto-generated method stub

         int []a={100,88,79,98};

            mp(a);

            for (int i = 0; i < a.length; i++) {

                System.out.println(a[i]);

            }

    }

        public static void mp(int[]b){

            for (int i = 0; i < b.length - 1; i++) {

                for (int j = 0; j < b.length - 1 - i; j++) {

                    if (b[j] > b[j + 1]) {

                        int temp = b[j];

                        b[j] = b[j + 1];

                        b[j + 1] = temp;

                    }

                }

            }

        }

    

}

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 mrb;

 

public class Asd {

   /**

     * @param args

     */

    public static void main(String[] args) {

        // TODO Auto-generated method stub

         int sum=jc(6);

         System.out.println(sum);

     }

     public static int jc(int a){

         int sum=1;

         for (int i =1; i <=a; i++) {

             sum*=i;

         }

         return sum;

         

 

     }

 

 }

 

3.编写一个方法，判断该年份是平年还是闰年。[必做题]

 

package mrb;

import java.util.Scanner;

public class Asd {

   /**

     * @param args

     */

    public static void main(String[] args) {

        // TODO Auto-generated method stub

           year();

    }

    public static void year(){

        Scanner input=new Scanner(System.in);

        System.out.println("请输入年份");

        int year=input.nextInt();

        if(year%4==0&&year%10!=0||year%400==0){

            System.out.println("是闰年");

        }else{

            System.out.println("是平年");

        }

        

    }

 

}

 

4.课堂没完成的menu菜单，实现幸运抽奖功能

package mrb;

import java.util.Random;

import java.util.Scanner;

public class Asd {

   /**

     * @param args

     */

    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("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:

                login();

                break;

            case 2:

                reg();

                break;

            case 3:

                lucky();

            

            }

            

            

        }

        

        private static void lucky() {

            // 输入四位会员卡号，如果百位数等于随机数，幸运会员。否则不是。同时也要询问是否返回主菜单

 

            Scanner input=new Scanner(System.in);

            System.out.println("请输入四位会员卡号");

            Random r=new Random();

            int x=r.nextInt(100);

            int a=input.nextInt();

            while(a<1000||a>10000){

                System.out.println("请重新输入");

                a=input.nextInt();

                if(a<1000||a>10000){

                    break;

                }    

            }

            int bw=a%1000/100;

            if(bw==x){

                System.out.println("恭喜成为幸运会员");

             }else{

                System.out.println("很遗憾不是幸运会员");

            }

            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 reg() {

            // 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 upwd=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 upwd=input.next();

            if(uname.equals("zs")&&upwd.equals("123")){

                System.out.println("ok");

            }else{

                System.out.println("fail");

            }

            returnMain();        

        }

        

    

}