四则运算2

import java.util.*;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class ArithmeticQuiz {
private static final int NUMBER_OF_QUESTIONS = 10;
private static final int TIME_LIMIT_PER_QUESTION = 30; // seconds
private static List questions = new ArrayList<>();
private static int correctAnswers = 0;
private static int wrongAnswers = 0;
private static Scanner scanner = new Scanner(System.in);

public static void main(String[] args) {
    generateQuestions();
    startQuiz();
    showResults();
}

private static void generateQuestions() {
    Set<String> uniqueQuestions = new HashSet<>();
    Random random = new Random();
    
    while (questions.size() < NUMBER_OF_QUESTIONS) {
        int type = random.nextInt(4); // 0: +, 1: -, 2: *, 3: /
        int num1 = random.nextInt(100) + 1; // 1 to 100
        int num2 = random.nextInt(100) + 1; // 1 to 100
        int answer = 0;
        String questionText = "";
        
        switch (type) {
            case 0: // Addition
                answer = num1 + num2;
                questionText = num1 + " + " + num2;
                break;
            case 1: // Subtraction
                if (num1 >= num2) {
                    answer = num1 - num2;
                    questionText = num1 + " - " + num2;
                }
                break;
            case 2: // Multiplication
                answer = num1 * num2;
                if (answer < 10000) {
                    questionText = num1 + " * " + num2;
                }
                break;
            case 3: // Division
                if (num2 != 0 && num1 % num2 == 0) {
                    answer = num1 / num2;
                    questionText = num1 + " / " + num2;
                }
                break;
        }
        
        if (!questionText.isEmpty() && uniqueQuestions.add(questionText)) {
            questions.add(new ArithmeticQuestion(questionText, answer));
        }
    }
}

private static void startQuiz() {
    ScheduledExecutorService executor = Executors.newScheduledThreadPool(1);
    
    for (ArithmeticQuestion question : questions) {
        System.out.println("Question: " + question.question);
        executor.schedule(() -> {
            System.out.println("Time's up! Moving to the next question.");
            wrongAnswers++;
            askQuestion(false, question); 
        }, TIME_LIMIT_PER_QUESTION, TimeUnit.SECONDS);
        
        boolean answered = askQuestion(true, question);
        if (answered) {
            executor.shutdownNow();
            executor = Executors.newScheduledThreadPool(1); // Create a new executor for the next question
        }
    }
    
    executor.shutdownNow();
}

private static boolean askQuestion(boolean waitForAnswer, ArithmeticQuestion question) {
    if (waitForAnswer) {
        System.out.print("Your answer: ");
        int userAnswer = scanner.nextInt();
        if (userAnswer == question.answer) {
            correctAnswers++;
            System.out.println("Correct!");
        } else {
            wrongAnswers++;
            System.out.println("Wrong! Correct answer was: " + question.answer);
        }
        return true; // User has answered
    }
    return false; // Time's up, user didn't answer
}

private static void showResults() {
    System.out.println("\nQuiz Results:");
    System.out.println("Correct Answers: " + correctAnswers);
    System.out.println("Wrong Answers: " + wrongAnswers);
    double accuracy = ((double) correctAnswers / (correctAnswers + wrongAnswers)) * 100;
    System.out.printf("Accuracy: %.2f%%\n", accuracy);
}

}

class ArithmeticQuestion {
String question;
int answer;

ArithmeticQuestion(String question, int answer) {
    this.question = question;
    this.answer = answer;
}

}