Java第十周作业

1. 编写一个方法，实现冒泡排序（由小到大），并调用该方法

 

public class Maopao {

public static void asdcr(int a[]){

 

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

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

if(a[i]<a[j]){

int max;

max = a[j];

a[j] = a[i];

a[i] = max;

}

}

}

}

 

public static void main(String[] args){

int a[] =new int[]{3,2,1,6,7,5};

asdcr(a);

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]

import java.util.Scanner;

 

public class Jc {

static Scanner input = new Scanner(System.in);

public static void asddr(){

System.out.println("请输入数字");

int b = input.nextInt();

int sum = 1;

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

sum*=i;

}

System.out.println(b+"的阶乘为"+sum);

}

public static void main(String[] args){

asddr();

}

 

}

 

3.编写一个方法，判断该年份是平年还是闰年。[必做题]

import java.util.Scanner;

 

public class Year {

static Scanner input = new Scanner(System.in);

public static void asder(){

System.out.println("请输入年份");

int a = input.nextInt();

if(a%400==0||(a%4==0&&a%100!=0)){

System.out.println("是闰年");

}else{

System.out.println("不是闰年");

}

}

 

public static void main(String[] args){

asder();

}

 

}

 

4.课堂没完成的menu菜单，实现幸运抽奖功能

import java.util.Scanner;

 

 

public class Menu {

 

private static Scanner  input;

private static Scanner input2;

private static Scanner input3;

private static Scanner input4;

private static Scanner input5;

 

 

 

public static void mainMenu(){

 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() {

input5 = new Scanner(System.in);

System.out.println("输入四位会员卡号");

int i = input5.nextInt();

int j = i/100%10;

if(j == (int) (Math.random() * 100)){

System.out.println("恭喜您的卡号成为幸运数字");

}else{

System.out.println("恭喜您的卡号未成为幸运数字");

returnMain();

}

}

 

public static void returnMain(){

input2 = new Scanner(System.in);

System.out.println("是否返回主菜单？");

if(input2.next().equalsIgnoreCase("Y"))

mainMenu();

else

System.out.println("谢谢使用");

}

 

public static void reg() {

input3 = new Scanner(System.in);

System.out.println("输入要注册的用户名");

String uname=input3.next();

System.out.println("输入注册密码");

String upwd=input3.next();

System.out.println("注册成功");

returnMain();

 

 

}

 

 

public static void login(){

input4 = new Scanner(System.in);

System.out.println("输入用户名");

String uname=input4.next();

System.out.println("输入密码");

String upwd=input4.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();

 

}

 

 

}