10

1.

package sr5;

public class t1 {
  public static void px(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;
            }
        }
    }
  }
     public static void main(String[] args){
         int x[]={34,75,91,43,61};
         px(x);
         for (int i = 0; i < x.length; i++) {
            System.out.println(x[i]);
        }
     }
}

 

 2.

package sr5;

public class t2 {
   public static int JC(int a){
       int sum=1;
       for (int i = 1; i < a+1; i++) {
        sum*=i;    
    }
       return sum;
   }
   public static void main(String[] args){
       System.out.println(JC(7));
   }
}

 

 3.

package sr5;

import java.util.Scanner;

public class t3 {
    public static void pd(int year) {
        if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {
            System.out.println("闰年");
        } else {
            System.out.println("平年");
        }
    }
 
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("输入年份");
        pd(input.nextInt());
    }
}

 

4.

package sr5;

import java.util.Scanner;

public class t4 {
     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
            Scanner input=new Scanner(System.in);
            System.out.println("请输入一个四位数");
            int a=input.nextInt();
            Random r=new Random();
            int x=r.nextInt(10);
            int baiwei=a%1000/100;
            while(a<1000||a>10000){
                System.out.println("输入错误，请重新输入");
                a=input.nextInt();
                if(a>=1000&&a<10000){
                    break;
                }
            }
                if(baiwei==x){
                    System.out.println("幸运会员");
                }else{
                    System.out.println("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();      
        }
         
     
         
        public static void main(String[] args) {
            mainMenu();
     
        }
}