第九次作业

1.编写一个方法，实现冒泡排序（由小到大），并调用该方法

package a;

public class a {
     public static void main(String[] args) {
         int[] array={1,2,5,3,10,21,0};
         maopao(array);
     }
     public static void maopao(int[] array){
         for (int i = 0; i <array.length; i++) {
             for(int j=0;j<array.length-i-1;j++){
                 if(array[j]>array[j+1]){
                     int temp=array[j];
                     array[j]=array[j+1];
                     array[j+1]=temp;
                 }
             }
         }
         System.out.print("从小到大为：");
         for (int i = 0; i < array.length; i++) {
             if(i==array.length-1){
                 System.out.println(array[i]);
             }else{
                 System.out.print(array[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 a;

public class b {
    public static void main(String[] args) {
        b p=new b();
        p.method(5);
        }
        public void method(int a) {
        int b=1;
        for(int i=1;i<=a;i++) {
        b*=i;
        }
        a=b;
        System.out.println(a);
 }                    
}

 

 3.编写一个方法，判断该年份是平年还是闰年。[必做题]

package a;

public class c {
    public static void main(String[] args) {
        c p = new c();
            p.method(2000);
        }
        public void method(int year) {
            int a;
            a=year;
            if(a%4==0 && a%100!=0 || a%400==0) {
                System.out.println(a+"是闰年");
            }else {
                System.out.println(a+"不是闰年");
            }

    }
}

 

 

4.课堂没完成的menu菜单，实现幸运抽奖功能

package a;
    import java.util.Random;
    import java.util.Scanner;
    public class test1 {
        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.退出系统");
            System.out.println("请选择");
            int i = input.nextInt();
            switch (i) {
            case 1:
                login();
                break;
            case 2:
                zhuce();
                break;
            case 3:
                xingyuncj();
                break;
            case 4:
                tuichu();
                break;
                
            }
        }

        public static void login() {
            // TODO Auto-generated method stub
            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("登录成功");
            } else {
                System.out.println("登录失败");
            }
            returnMain();
        
        }
        public static void zhuce() {
            Scanner input = new Scanner(System.in);
            System.out.println("用户名");
            String uname = input.next();
            System.out.println("密码");
            String upwd = input.next();
            if(uname.equals(null) || upwd.equals(null) ) {
                System.out.println("注册失败");
            }else {
                System.out.println("注册成功");
            }
            returnMain();
        }
        public static void xingyuncj() {
            System.out.println("1.作弊模式");
            System.out.println("2.正常模式");
            Scanner input = new Scanner(System.in);
            int x=input.nextInt();
            switch(x) {
            case 1:
                zuobi();
                break;
            case 2:
                zhengchang();
                break;
            }
        }
        public static void zuobi() {
            Scanner input = new Scanner(System.in);
            System.out.println("作弊模式：");
            Random r=new Random();
            int sjs=r.nextInt(10);
            System.out.println(sjs);
            System.out.println("请输入四位会员数");
            int num=input.nextInt();
            if(num/100%10==sjs) {
                System.out.println("恭喜你，是幸运会员");
            }else {
                System.out.println("祝你下次好运");
            }
            returnMain();
        }
        public static void zhengchang() {
            Scanner input = new Scanner(System.in);
            System.out.println("正常模式");
            Random r=new Random();
            int sjs=r.nextInt(10);
            System.out.println("请输入四位会员数");
            int num=input.nextInt();
            if(num/100%10==sjs) {
                System.out.println("恭喜你，是幸运会员");
            }else {
                System.out.println("祝你下次好运");
            }
            returnMain();
        }

        public static void tuichu() {
            System.out.println("是否退出系统Y/N");
            Scanner input = new Scanner(System.in);
            String a = input.next();
            if(a.equalsIgnoreCase("y")) {
                System.out.println("退出系统成功");
            }else {
                returnMain();
            }
        } 
        
        public static void returnMain(){
            System.out.println("是否返回主菜单?Y/N");
            Scanner input = new Scanner(System.in);
            if (input.next().equalsIgnoreCase("Y")) {
                mainMenu();
            }else{
                System.out.println("谢谢使用");
            }

        }
    }