java第十次作业

Teacher丹丹 发布于 2021-05-07 10:00 ，截止时间 2021-05-12 20:00，剩余 4小时
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

Scanner input = new Scanner(System.in);
System.out.println("输入5个数：");
int a[] = new int[5];
int b;
for (int i = 0; i < a.length; i++) {
a[i] = input.nextInt();
}
for (int i = 0; i < a.length - 1; i++) {
for (int j = i+1; j < a.length; j++) {
if (a[i] > a[j]) {
b = a[i];
a[i] = a[j];
a[j] = b;
}
}
}
for (int i = 0; i < a.length; i++) {
System.out.print(a[i]);
System.out.print(" ");
}
System.out.println();

 

 

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]

int sum1=jc(5);

        System.out.println(sum1);

    }

    public static int jc(int n){

        int sum=1;

        for (int i =1; i <=n; 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]

public static void ss() {
Scanner input=new Scanner(System.in);
int a=input.nextInt();
if (a % 400 == 0 & a % 100 != 0 | a % 4 == 0)
System.out.println("闰年");
else
System.out.println("平年");
}
public static void main(String[] args) {
ss();

 

 

4.课堂没完成的menu菜单，实现幸运抽奖功能

public static void SY() {
                Scanner input = new Scanner(System.in);
                System.out.println("<<<<<<<<<<欢迎使用会员抽奖系统>>>>>>>>>>");
                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("    请输入数字编号进行操作");
                int i = input.nextInt();
                switch (i) {
                case 1:
                    login();
                    break;
                case 2:
                    reg();
                    break;
                case 3:
                    lucky();
                default:
                    System.out.println("输入错误，请重新输入！");
                    SY();
         
                }
         
            }
         
            private static void lucky() {
    
                Scanner input = new Scanner(System.in);
                Random r = new Random();
                int luck = r.nextInt(10);
                System.out.println("请输入四位会员卡号");
                int id = input.nextInt();
                if (luck == id) {
                    System.out.println("恭喜您是幸运会员");
                } else {
                    System.out.println("对不起您不是幸运会员");
                }
                returnMain();
            }
         
            public static void returnMain() {
                Scanner input = new Scanner(System.in);
                System.out.println("是否返回主菜单？（Y/S）");
                if (input.next().equalsIgnoreCase("Y"))
                    SY();
                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("123") && upwd.equals("123")) {
                    System.out.println("输入正确");
                } else {
                    System.out.println("输入错误");
                }
                returnMain();
            }
         
            public static void main(String[] args) {
                SY();