第九次java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 usb;

import java.util.Scanner;


public class maopao {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
Scanner input=new Scanner(System.in);
System.out.println("请输入六个数");
int a[]=new int[6];
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 temp=a[j];
a[j]=a[j+1];
a[j+1]=temp;

        
    }
    }
}
System.out.println("排序后结果为:");
for (int i = 0; i < a.length; i++) {
    System.out.println(a[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 usb;

import java.util.Scanner;


public class maopao {
     public static int jiecheng(int a) {
         int sum = 1;
         for (int i = 1; i <= a ; i++) {
             sum *= i;
         }
         System.out.println(+a+"的阶乘是");
         return sum;
     }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
System.out.println(jiecheng(6));
    }
    
}

 

 

 

3.编写一个方法，判断该年份是平年还是闰年。[必做题]、

package usb;
import java.util.Scanner;
public class nianfen {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
Scanner input=new Scanner(System.in);
System.out.println("请输入一个年份:");
int year=input.nextInt();
if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) 
{
    
    System.out.println("闰年");
}
    else 
    {
        System.out.println("平年");
    }
    
    }
}

 

 

4.课堂没完成的menu菜单，实现幸运抽奖功能

package usb;
import java.util.Random;
import java.util.Scanner;

public class maopao{

    /**
     * @param args
     */
    public static void main(String[] args) {
        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() {   
            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();        
        }
        
    
    }