第十周第九次

编写一个方法，实现冒泡排序（由小到大），并调用该方法
package dijiucizuoye;
 2 
 3 import java.util.Scanner;
 4 
 5 public class work {
 6     public static void px(int []a) {
 7         for (int i = 0; i < a.length; i++) {
 8             for(int j=0;j<a.length;j++){
 9                 if (a[i]<a[j]) {
10                 int temp=a[i];
11                 a[i]=a[j];
12                 a[j]=temp;
13                 }
14             }
15 
16         }
17     }
18     public static void main(String[] args){
19         Scanner input=new Scanner(System.in);
20         int []a=new int [5];
21         for(int i=0;i<a.length;i++){
22             a[i]= input.nextInt();
23         }
24         px(a);
25         for (int i = 0; i <a.length ; i++) {
26             System.out.print(a[i]+" ");
27         }
28     }
29 }

 

 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

 package dijiucizuye;
 2 
 3 import java.util.Scanner;
 4 
 5 public class Sclass {
 6     public static int jc(int a) {
 7         int sum=1;
 8         for (int i = 1; i <=a ; i++) {
 9             sum*=i;
10         }
11         return sum;
12     }
13 
14     public static void main(String[] args){
15         Scanner input=new Scanner(System.in);
16         int n=input.nextInt();
17         System.out.println(jc(n));
18     }
19 }

 

 编写一个方法，判断该年份是平年还是闰年

 package dijiucizuoye;
 2 
 3 import java.util.Scanner;
 4 
 5 public class A {
 6     public static void pd(int year){
 7         if (year%4==0&&year%100!=0||year%400==0) {
 8             System.out.println("闰年");
 9         }
10         else {
11             System.out.println("平年");
12         }
13     }
14 
15 
16     public static void main(String[] args) {
17         Scanner input=new Scanner(System.in);
18         pd(input.nextInt());
19     }
20 }

 

 

 

package dijiucizuoye;
 2 
 3 import java.util.Random;
 4 import java.util.Scanner;
 5 
 6 public class work4 {
 7     public static void mainMenu(){
 8         Scanner input=new Scanner(System.in);
 9         System.out.println("欢迎使用本系统");
10         System.out.println("1.登录");
11         System.out.println("2.注册");
12         System.out.println("3.幸运抽奖");
13         System.out.println("4.退出");
14         System.out.println("请选择");
15         int i=input.nextInt();
16         switch(i){
17             case 1:
18                 login();
19                 break;
20             case 2:
21                 reg();
22                 break;
23             case 3:
24                 lucky();
25                 break;
26         }
27 
28 
29     }
30 
31     public static void returnMain(){
32         Scanner input=new Scanner(System.in);
33         System.out.println("是否返回主菜单？");
34         if(input.next().equalsIgnoreCase("Y"))
35             mainMenu();
36         else
37             System.out.println("谢谢使用");
38     }
39 
40     public static void reg() {
41         // TODO Auto-generated method stub
42         Scanner input=new Scanner(System.in);
43         System.out.println("输入要注册的用户名");
44         String uname=input.next();
45         System.out.println("输入注册密码");
46         String upwd=input.next();
47         System.out.println("注册成功");
48 
49         returnMain();
50 
51     }
52 
53 
54     public static void login(){
55         Scanner input=new Scanner(System.in);
56         System.out.println("输入用户名");
57         String uname=input.next();
58         System.out.println("输入密码");
59         String upwd=input.next();
60         if(uname.equals("zs")&&upwd.equals("123")){
61             System.out.println("ok");
62         }else{
63             System.out.println("fail");
64         }
65         returnMain();
66     }
67     private static void lucky() {
68         // 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
69         Scanner input=new Scanner(System.in);
70         Random r=new Random();
71         int luck=r.nextInt(10);
72         System.out.println("幸运数字为"+luck);
73         System.out.println("输入四位数会员卡号");
74         int id= input.nextInt();
75         if (id/100%10==luck) {
76             System.out.println("幸运会员是"+id+"号");
77         }
78         else {
79             System.out.println("不是幸运会员");
80         }
81         returnMain();
82     }
83 
84 
85     public static void main(String[] args) {
86         mainMenu();
87 
88     }
89 
90 
91 }