第十周作业5.11

老师：Teacher丹丹 提交作业

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1.编写一个方法，实现冒泡排序（由小到大），并调用该方法

package week10;

public class M1 {
    public static void maopao(int []a){
        
        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 temp=a[j];
                    a[j]=a[j+1];
                    a[j+1]=temp;
                }
            }
        }
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int x[]={4,6,2,9,5,1,};
        maopao(x);
        for (int i = 0; i < x.length; i++) {
            System.out.println(x[i]);
        }
        
    }

}

 

 

 

 

 

 

 

 

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 week10;

public class M2 {

    public static int jiecheng(int n){
        int sum=1;
        for (int i=n; i>0; i--) {
            sum=sum*i;
            
            
        }
        return sum;
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println(jiecheng(5));

    }

}

 

 

3.编写一个方法，判断该年份是平年还是闰年。[必做题]

package week10;

import java.util.Scanner;

public class M3 {

    public static void nianfen(int year){
        if(year%4==0&&year%100!=0||year%400==0)
            System.out.println("该年为闰年");
        else
            System.out.println("该年为平年");
        
    }
    
    public static void main(String[] args) {
        // TODO Auto-generated method stub(能被4整除但不能被100整除,或者能被400整除)
        Scanner input=new Scanner(System.in);
        System.out.println("请输入年份");
        int year=input.nextInt();
        nianfen(year);
        
    }

}

 

 

 

4.课堂没完成的menu菜单，实现幸运抽奖功能

package week10;
import java.util.Random;

import java.util.Scanner;

public class M4 {

    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();
        
        }
        
        
    }
    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");
    }
    
    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);
        Random r=new Random();
        int x=r.nextInt(9);
        System.out.println("随机数为"+x);
        System.out.println("输入四位会员卡号");
        int unum=input.nextInt();
        if(unum/100%10==x){
            System.out.println("幸运会员");}
        else
            {
                System.out.println("不是会员");
            }
            returnMain();
        }
    
    
    
    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();        
    }
    

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

    }
    

}