10.24

package 测试;
import java.util.;
import javax.swing.JOptionPane;
import java.io.;

public class MathTest {
static final Random R = new Random();
// 存储题目和答案
static List questions = new ArrayList<>();
static List answers = new ArrayList<>();
// 存储用户答案
static List userAnswers = new ArrayList<>();
// 存储错题索引
static List wrongIndexes = new ArrayList<>();

public static void main(String[] args) {
    generateAndSaveQuestions();
    List<Double> userInputs = getAndCheckAnswers();
    
    // 统计结果
    int wrongCount = 0;
    StringBuilder resultMessage = new StringBuilder();
    for (int i = 0; i < questions.size(); i++) {
        double std = answers.get(i);
        double userAnswer = userInputs.get(i);
        String feedback;
        if (Math.abs(userAnswer - std) < 1e-6) {
            feedback = "正确";
        } else {
            feedback = "错误，正确答案：" + (std % 1 == 0 ? (long) std : std);
            wrongCount++;
            wrongIndexes.add(i);
        }
        resultMessage.append((i + 1)).append(". ").append(questions.get(i)).append(userAnswer).append(" → ").append(feedback).append("\n");
    }
    double accuracy = (questions.size() - wrongCount) * 100.0 / questions.size();
    resultMessage.append("\n------------------\n")
            .append(String.format("错题数：%d / %d，正确率：%.2f%%", wrongCount, questions.size(), accuracy));

    JOptionPane.showMessageDialog(null, resultMessage.toString(), "测验结果", JOptionPane.INFORMATION_MESSAGE);

    // 错题二次答题
    if (!wrongIndexes.isEmpty()) {
        int choice = JOptionPane.showConfirmDialog(null, "是否进行错题二次答题？", "提示", JOptionPane.YES_NO_OPTION);
        if (choice == JOptionPane.YES_OPTION) {
            redoWrongQuestions();
        }
    }

    // 数据库连接（这里只是示例，需根据实际数据库修改）
    if (connectDatabase()) {
        JOptionPane.showMessageDialog(null, "数据库连接成功，直接过关！", "提示", JOptionPane.INFORMATION_MESSAGE);
    } else {
        JOptionPane.showMessageDialog(null, "数据库连接失败。", "提示", JOptionPane.INFORMATION_MESSAGE);
    }
}

// 生成题目并保存到文本文件
private static void generateAndSaveQuestions() {
    try (PrintWriter writer = new PrintWriter(new FileWriter("math_questions.txt"))) {
        StringBuilder line = new StringBuilder();
        for (int i = 1; i <= 30; i++) {
            String exp = generateExpression();
            double std = calculate(exp);
            questions.add(exp);
            answers.add(std);
            line.append(exp).append(" ");
            if (i % 3 == 0) {
                writer.println(line.toString().trim());
                line = new StringBuilder();
            }
        }
        if (line.length() > 0) {
            writer.println(line.toString().trim());
        }
    } catch (IOException e) {
        JOptionPane.showMessageDialog(null, "题目保存失败：" + e.getMessage(), "错误", JOptionPane.ERROR_MESSAGE);
        System.exit(1);
    }
}

// 获取用户答案并判读
private static List<Double> getAndCheckAnswers() {
    List<Double> userInputs = new ArrayList<>();
    try (BufferedReader reader = new BufferedReader(new FileReader("math_questions.txt"))) {
        String line;
        int questionIndex = 0;
        while ((line = reader.readLine()) != null && questionIndex < 30) {
            String[] qs = line.split(" ");
            for (String q : qs) {
                if (questionIndex >= 30) break;
                String exp = q;
                double std = calculate(exp);
                String userInput = JOptionPane.showInputDialog(null,
                        (questionIndex + 1) + ". " + exp,
                        "数学测验 - 第" + (questionIndex + 1) + "题",
                        JOptionPane.QUESTION_MESSAGE);
                if (userInput == null) {
                    JOptionPane.showMessageDialog(null, "测验已取消", "提示", JOptionPane.INFORMATION_MESSAGE);
                    System.exit(0);
                }
                double userAnswer;
                try {
                    userAnswer = Double.parseDouble(userInput);
                } catch (NumberFormatException e) {
                    userAnswer = Double.NaN;
                }
                userInputs.add(userAnswer);
                questionIndex++;
            }
        }
    } catch (IOException e) {
        JOptionPane.showMessageDialog(null, "题目读取失败：" + e.getMessage(), "错误", JOptionPane.ERROR_MESSAGE);
        System.exit(1);
    }
    return userInputs;
}

// 错题二次答题
private static void redoWrongQuestions() {
    int newWrongCount = 0;
    StringBuilder redoResult = new StringBuilder();
    redoResult.append("错题二次答题结果：\n");
    for (int index : wrongIndexes) {
        String exp = questions.get(index);
        double std = answers.get(index);
        String userInput = JOptionPane.showInputDialog(null,
                "错题重答 - " + (index + 1) + ". " + exp,
                "数学测验 - 错题重答",
                JOptionPane.QUESTION_MESSAGE);
        if (userInput == null) break;
        double userAnswer;
        try {
            userAnswer = Double.parseDouble(userInput);
        } catch (NumberFormatException e) {
            userAnswer = Double.NaN;
        }
        String feedback;
        if (Math.abs(userAnswer - std) < 1e-6) {
            feedback = "正确";
        } else {
            feedback = "错误，正确答案：" + (std % 1 == 0 ? (long) std : std);
            newWrongCount++;
        }
        redoResult.append((index + 1)).append(". ").append(exp).append(userAnswer).append(" → ").append(feedback).append("\n");
    }
    redoResult.append("\n二次答题后，仍错误数：").append(newWrongCount);
    JOptionPane.showMessageDialog(null, redoResult.toString(), "错题二次答题结果", JOptionPane.INFORMATION_MESSAGE);
}

// 数据库连接（示例，需根据实际数据库修改）
private static boolean connectDatabase() {
    // 这里只是模拟数据库连接，实际需使用JDBC等方式连接真实数据库
    // 例如：
    // try {
    //     Class.forName("com.mysql.jdbc.Driver");
    //     Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/dbname", "username", "password");
    //     conn.close();
    //     return true;
    // } catch (Exception e) {
    //     return false;
    // }
    // 现在简单返回true模拟连接成功
    return true;
}

private static String generateExpression() {
    int a = 0, b = 0, opType;

    while (true) {
        opType = R.nextInt(4);
        switch (opType) {
            case 0:
                a = 1 + R.nextInt(100);
                b = 1 + R.nextInt(100);
                break;
            case 1:
                a = 1 + R.nextInt(100);
                b = 1 + R.nextInt(a);
                break;
            case 2:
                a = 1 + R.nextInt(31);
                b = 1 + R.nextInt(31);
                if (a * b > 999) continue;
                break;
            case 3:
                b = 1 + R.nextInt(100);
                int q = 1 + R.nextInt(100 / b + 1);
                a = q * b;
                break;
        }
        break;
    }
    char operator = "+-*/".charAt(opType);
    return "" + a + operator + b + "=";
}

private static double calculate(String exp) {
    String[] parts = exp.split("[-+*/=]");
    int a = Integer.parseInt(parts[0]);
    int b = Integer.parseInt(parts[1]);
    char op = exp.replaceAll("[0-9]|=", "").charAt(0);

    switch (op) {
        case '+':
            return a + b;
        case '-':
            return a - b;
        case '*':
            return a * b;
        case '/':
            return (double) a / b;
        default:
            return 0;
    }
}

}