5.7 第10周第9次java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
1 package sjw; 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 }
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]
1 package sjw; 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 }
3.编写一个方法,判断该年份是平年还是闰年。[必做题]
1 package sjw; 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 }
4.课堂没完成的menu菜单,实现幸运抽奖功能
1 package sjw; 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 }