2020-4-29

package hm_4_29;
/*
 * 第一题
 */
import java.util.Random;
import java.util.Scanner;

public class Demo01 {

    public static void main(String[] args) {
        mainMenu();
    }
    public static void mainMenu() {
        //选择服务
        Scanner sc = 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.看小故事");
        System.out.println("5.退出系统");
        System.out.println("请选择");
        int i = sc.nextInt();
        switch (i) {
        case 1:
            login();
            break;
        case 2:
            zhuce();
            break;
        case 3:
            choujiang();
            break;
        case 4:
            read();
            break;
        case 5:
            exit();
            break;
        }
    }

    private static void login() {
        Scanner sc = new Scanner(System.in);
        System.out.println("输入用户名");
        String uname = sc.next();
        System.out.println("输入密码");
        String upwd = sc.next();
        if (uname.equals("wang") && upwd.equals("wang12340.")) {
            System.out.println("登录成功");
        } else {
            System.out.println("登录失败");
        }
        returnMain();
    }
    
    private static void zhuce() {
        Scanner zc = new Scanner(System.in);
        System.out.println("输入用户名：");
        String name = zc.nextLine();
        System.out.println("输入密码");
        String psw = zc.nextLine();
        System.out.println("注册成功");
        returnMain();
    }
    
    private static void choujiang() {
        Scanner hy = new Scanner(System.in);
        System.out.print("请输入四位会员号：");
        Random sj = new Random();
        int sjs = sj.nextInt();
        int hynum = hy.nextInt();
        if(hynum/100%10==sjs) {
            System.out.println("您是星选会员！");
        }else {
            System.out.println("您不是星选会员！");
        }
        returnMain();
    }
    
    private static void read() {
        System.out.println("请选择故事：");
        System.out.println("1.青蛙王子");
        System.out.println("2.狼来了");
        Scanner rd = new Scanner(System.in);
        int gs = rd.nextInt();
        switch(gs) {
        case 1:
            System.out.println("您选择的是青蛙王子");
            break;
        case 2:
            System.out.println("您选择的是狼来了");
            break;
        default:
            System.out.println("重新选择。");
            read();
            break;
        }
        returnMain();
    }
    
    private static void exit() {
        System.out.println("成功退出系统！再见！");
    }
    
    public static void returnMain(){
        System.out.println("是否返回主菜单?Y/N");
        Scanner sc = new Scanner(System.in);
        if (sc.nextLine().equalsIgnoreCase("Y")) {
            mainMenu();
        }else if(sc.nextLine().equalsIgnoreCase("N")){
            System.out.println("谢谢使用");
        }
    }
}
package hm_4_29;
/*
 * 求阶乘
 */
import java.util.Scanner;

public class Demo02 {
    public static void main(String[] args) {
            stratum();
    }
    public static void stratum() {
        Scanner sc = new Scanner(System.in);
        System.out.print("请输入一个数：");
        int a = sc.nextInt();
        int sum=1;
        for(int i =1 ;i<=a;i++) {
            sum*=i;
        }
        System.out.println("阶乘："+sum);
    }
}
package hm_4_29;

import java.util.Scanner;

public class Demo03 {
/*
 * 判断闰年
 */
    public static void main(String[] args) {
                leapYear();
    }
     private static void leapYear() {
            Scanner sc = new Scanner(System.in);
            System.out.println("请输入一个年份：");
            int year = sc.nextInt();
            if(year %400 ==0 ||(year %4==0&& year%100!=0)) {
                
            }else {
                System.out.print("不");
            }
            System.out.println("是闰年");
}
}