1.完善menu的注册功能，抽奖以及讲小故事等功能。
package wsh;
import java.util.Scanner;
import java.util.Random;
public class xitong {
public static void main(String[] args) {
// TODO Auto-generated method stub
mainMenu();
}
public static void mainMenu() {
Scanner input =new Scanner(System. in);
System.out.println("1.登录");
System.out.println("2.注册");
System.out.println("3.幸运抽奖");
System.out.println("4.小故事");
System.out.println("5.退出系统");
System.out.println("请选择");
int i = input.nextInt();
switch (i){
case 1:
register();
break;
case 2:
login();
break;
case 3:
cj();
break;
case 4:
story();
break;
case 5:
returnmain();
break;
}
}
public static void register() {
Scanner input = new Scanner(System.in);
System.out.println("输入用户姓名");
String uname=input.next();
System.out.println("输入密码");
String upwd=input.next();
if(uname.equals("zs")&& upwd.equals("123456")){
System.out.println("登录成功");
}else{
System.out.println("登录失败");
}
returnmain();
}
public static void login(){
Scanner input = new Scanner(System.in);
System.out.println("注册姓名");
String zname=input.next();
System.out.println("注册密码");
String zpwd=input.next();
System.out.println("注册成功！");
returnmain();
}
public static void cj(){
Random r=new Random ();
Scanner input=new Scanner(System.in);
System.out.println("请输入四位会员号");
int huiyuan=input.nextInt();
int bai=huiyuan/100%10;
int lucky=r.nextInt(10);
if(bai==lucky){
System.out.println("恭喜您，中奖了");
}else{
System.out.println("很抱歉，您不是幸运会员");
}
returnmain();
}
public static void story(){
System.out.println("从前有座山，山上有座庙，庙里有个老和尚在讲故事。");
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，再见");
}
}
}
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。
package wsh;
public class qita {
public static int jc(int a){
int sum=1;
for (int i = 1; i <=a; i++) {
sum*=a;
}
return sum;
}
public static void main(String[] args) {
System.out.println(jc(6));
}
}
3.编写一个方法，判断该年份是平年还是闰年。
package wsh;
public class qita {
public static void main(String[] args) {
near(2020);
}
public static void near(int y){
if (y % 4 == 0 && y % 100 != 0 || y % 400 == 0) {
System.out.println(y + "年是闰年");
} else {
System.out.println(y + "年不是闰年");
}
}
}
