java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 cn;

public class Test1 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int []x={1,3,2,5,8,7,9};
        mp(x);
        for (int i = 0; i < x.length; i++) {
            System.out.println(x[i]);
        }
    }
    public static void mp(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;
                }
            }
        }
    }
}

 

 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 work;

import java.util.Scanner;

public class test {
    public static void main(String[] args) {
        jc();
    }
    public static void jc() {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入整数：");
        int a = input.nextInt();
        int jie=1;
        for (int i = 1;  i<=a; i++) {
            jie*=i;
            
        }
        System.out.println(jie);
    }
}

 

 3.编写一个方法，判断该年份是平年还是闰年。[必做题]

package sj10;
import java.util.Scanner;
public class sj {
    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("输入年份");
          int year=input.nextInt();
          if(year%4==0&&year%100!=0||year%400==0){
             System.out.println(year+"是闰年");
             }else{
          System.out.println(year+"是平年");
         }
    }
}

 

 4.课堂没完成的menu菜单，实现幸运抽奖功能

package chap8;

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

public class Menu {
    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
        System.out.println("输入四位卡号");
        Scanner input =new Scanner(System.in);
        int card=input.nextInt();
        Random r=new Random();
        int a = r.nextInt(10);
        if(card / 100 % 10==a) {
            System.out.println("该用户为幸运会员");
        }else {
            System.out.println("该用户不是幸运会员");
        }
    }

    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();        
    }
    

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

    }
}