关于出四则运算题的进阶可视化解答

`import javax.swing.;
import javax.swing.border.TitledBorder;
import java.awt.;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.HashSet;
import java.util.Random;
import java.util.Scanner;

class QuizFrame extends JFrame {
private HashSet generatedProblems;
private int correctAnswers;
private int totalProblems;
private int wrongAnswers;
private Random random;
private long startTime;
private long endTime;
private int countdownTime;
private JTextField[][] answerFields;
private JLabel timeLabel;
private JButton submitButton;

public QuizFrame() {
    setTitle("四则运算测试");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLayout(new BorderLayout());

    random = new Random();
    generatedProblems = new HashSet<>();
    correctAnswers = 0;
    totalProblems = 30;
    wrongAnswers = 0;

    System.out.println("请输入做题时间");
    Scanner scanner = new Scanner(System.in);
    countdownTime = scanner.nextInt();
    if (countdownTime > 300 || countdownTime <= 0) {
        countdownTime = 60; // 默认一分钟
        System.out.println("输入时间不合法，采用默认一分钟倒计时。");
    }

    startTime = System.currentTimeMillis();
    endTime = startTime + countdownTime * 1000;

    JPanel mainPanel = new JPanel(new BorderLayout());

    JPanel problemPanel = new JPanel(new GridLayout(6, 5));
    problemPanel.setBorder(new TitledBorder("题目与答案"));

    answerFields = new JTextField[6][5];

    generateProblems();

    int index = 0;
    for (int i = 0; i < 6; i++) {
        for (int j = 0; j < 5; j++) {
            if (index < totalProblems) {
                JLabel problemLabel = new JLabel(generatedProblems.toArray()[index].toString() + " = ");
                problemPanel.add(problemLabel);

                JTextField answerField = new JTextField();
                answerFields[i][j] = answerField;
                problemPanel.add(answerField);
                index++;
            }
        }
    }

    mainPanel.add(problemPanel, BorderLayout.CENTER);

    timeLabel = new JLabel();
    mainPanel.add(timeLabel, BorderLayout.NORTH);

    submitButton = new JButton("提交");
    submitButton.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            checkAnswers();
        }
    });
    JPanel buttonPanel = new JPanel(new FlowLayout());
    buttonPanel.add(submitButton);
    mainPanel.add(buttonPanel, BorderLayout.SOUTH);

    add(mainPanel);

    Timer timer = new Timer(1000, new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            long remainingTime = (endTime - System.currentTimeMillis()) / 1000;
            if (remainingTime >= 0) {
                timeLabel.setText("剩余时间：" + remainingTime + " 秒");
            } else {
                timeLabel.setText("时间到！");
                checkAnswers();
            }
        }
    });
    timer.start();
}

private void generateProblems() {
    while (generatedProblems.size() < totalProblems) {
        int num1 = random.nextInt(100);
        int num2;
        int operatorIndex = random.nextInt(4);
        int result;
        String operator;
        String problem;

        switch (operatorIndex) {
            case 0:
                operator = "+";
                num2 = random.nextInt(100 - num1);
                result = num1 + num2;
                problem = num1 + " " + operator + " " + num2;
                break;
            case 1:
                operator = "-";
                num2 = random.nextInt(num1 + 1);
                result = num1 - num2;
                problem = num1 + " " + operator + " " + num2;
                break;
            case 2:
                operator = "*";
                do {
                    num2 = random.nextInt(100);
                } while (num1 * num2 >= 1000);
                result = num1 * num2;
                problem = num1 + " " + operator + " " + num2;
                break;
            default:
                operator = "/";
                num2 = random.nextInt(100) + 1;
                while (num1 % num2!= 0) {
                    num2 = random.nextInt(100) + 1;
                }
                result = num1 / num2;
                problem = num1 + " " + operator + " " + num2;
                break;
        }

        if (!generatedProblems.contains(problem)) {
            generatedProblems.add(problem);
        }
    }
}

private void checkAnswers() {
    if (correctAnswers == 0 && wrongAnswers == 0) {
        int index = 0;
        for (int i = 0; i < 6; i++) {
            for (int j = 0; j < 5; j++) {
                if (index < totalProblems) {
                    String problem = generatedProblems.toArray()[index].toString();
                    int expectedAnswer = calculateAnswer(problem);
                    try {
                        int userAnswer = Integer.parseInt(answerFields[i][j].getText());
                        if (userAnswer == expectedAnswer) {
                            correctAnswers++;
                        } else {
                            wrongAnswers++;
                        }
                    } catch (NumberFormatException ex) {
                        wrongAnswers++;
                    }
                    index++;
                }
            }
        }
        double accuracy = (double) correctAnswers / totalProblems * 100;
        int option = JOptionPane.showConfirmDialog(this, "答题结束。\n错题数：" + wrongAnswers + "\n正确率：" + accuracy + "%", "结果", JOptionPane.OK_CANCEL_OPTION);
        if (option == JOptionPane.OK_OPTION) {
            dispose();
        }
    }
}

private int calculateAnswer(String problem) {
    String[] parts = problem.split(" ");
    int num1 = Integer.parseInt(parts[0]);
    int num2 = Integer.parseInt(parts[2]);
    String operator = parts[1];

    switch (operator) {
        case "+":
            return num1 + num2;
        case "-":
            return num1 - num2;
        case "*":
            return num1 * num2;
        default:
            return num1 / num2;
    }
}

}

public class sice {
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
QuizFrame frame = new QuizFrame();
frame.pack();
frame.setVisible(true);
});
}
}`