package cn.jbit.dlc1;import java.util.Scanner;public class LuckyNumber5 {  /**   * 幸運抽獎   */  public static void main(String[] args) {    String answer = "y"; // 標識是否繼續    String userName = ""; // 用戶名    String password = ""; // 密碼    int cardNumber = 0; // 卡號    boolean isRegister = false; // 標識是否注冊    boolean isLogin = false; // 標識是否登錄    int max = 9999;    int min = 1000;    Scanner input = new Scanner(System.in);    do {      System.out.println("*****歡迎進入獎客富翁系統*****");      System.out.println("/t1.注冊");      System.out.println("/t2.登錄");      System.out.println("/t3.抽獎");      System.out.println("***************************");      System.out.print("請選擇菜單：");      int choice = input.nextInt();      switch (choice) {      case 1:        System.out.println("[獎客富翁系統 > 注冊]");        System.out.println("請填寫個人注冊信息：");        System.out.print("用戶名：");        userName = input.next();        System.out.print("密碼：");        password = input.next();        // 獲取4位隨機數作為卡號        cardNumber = (int)(Math.random()*(max-min))+min;        System.out.println("/n注冊成功，請記好您的會員卡號");        System.out.println("用戶名/t密碼/t會員卡號");        System.out.println(userName + "/t" + password + "/t" + cardNumber);        isRegister = true; // 注冊成功，標志位設置為true        break;      case 2:        System.out.println("[獎客富翁系統 > 登錄]");        if (isRegister) { // 判斷是否注冊          // 3次輸入機會          for (int i = 1; i <= 3; i++) {            System.out.print("請輸入用戶名：");            String inputName = input.next();            System.out.print("請輸入密碼：");            String inputPassword = input.next();            if (userName.equals(inputName) && password.equals(inputPassword)) {              System.out.println("/n歡迎您：" + userName);              isLogin = true; // 登錄成功，標志位設置為true              break;            } else if (i < 3) {              System.out.println("用戶名或密碼錯誤，還有" + (3 - i) + "次機會！");            } else {              System.out.println("您3次均輸入錯誤！");            }          }        } else {          System.out.println("請先注冊，再登錄！");        }        break;      case 3:        System.out.println("[獎客富翁系統 > 抽獎]");        if (!isLogin) { // 判斷是否登錄          System.out.println("請先登錄，再抽獎！");          System.out.println("繼續嗎？（y/n）");          answer = input.next();        } else {          //生成5個4位隨機數字，并保存在數組中          int[] luckynums = new int[5];          for(int i = 0; i < luckynums.length; i++){            luckynums[i] = (int)(Math.random()*(max-min))+min;          }          System.out.print("請輸入您的卡號：");          int yourcard = input.nextInt();          int i;          System.out.print("/n本日的幸運數字為：");          for (i = 0; i < luckynums.length; i++) {            System.out.print(luckynums[i] + " ");          }          for (i = 0; i < luckynums.length; i++) {            if (luckynums[i] == yourcard) {              System.out.println("/n恭喜！您是本日的幸運會員！");              break;            }          }          if (i == luckynums.length) {            System.out.println("/n抱歉！您不是本日的幸運會員！");          }        }        break;      default:        System.out.println("[您的輸入有誤！]");        break;      }      System.out.print("繼續嗎？（y/n）:");      answer = input.next();      System.out.println("");    } while ("y".equals(answer));    if ("n".equals(answer)) {      System.out.println("系統退出，謝謝使用！");    }  }}