用Java实现，生成100以内加法/减法的算式，批量产生习题并用文件存储，批改练习并存储

以下是Java实现的代码，生成100以内加法/减法的算式，批量产生习题并用文件存储，批改练习并存储的过程：

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Random;

public class MathExerciseGenerator {
    private static final int NUM_EXERCISES = 10; // 需要生成的练习数量
    private static final int MAX_NUM = 100; // 最大数值范围

    public static void main(String[] args) {
        // 生成练习并存储到文件
        generateExercises();
        System.out.println("练习已生成并存储到文件。");

        // 批改练习并存储到文件
        checkExercises();
        System.out.println("批改结果已存储到文件。");
    }

    private static void generateExercises() {
        File file = new File("exercises.txt");
        Random random = new Random();
        try (FileWriter writer = new FileWriter(file)) {
            for (int i = 1; i <= NUM_EXERCISES; i++) {
                int num1 = random.nextInt(MAX_NUM + 1);
                int num2 = random.nextInt(MAX_NUM + 1);
                int operation = random.nextInt(2); // 0表示加法，1表示减法
                String operator = (operation == 0) ? "+" : "-";
                int result = (operation == 0) ? (num1 + num2) : (num1 - num2);
                String exercise = String.format("%d %s %d = ", num1, operator, num2);
                writer.write(exercise);
                writer.flush();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static void checkExercises() {
        File file = new File("exercises.txt");
        File resultFile = new File("results.txt");
        try (FileWriter writer = new FileWriter(resultFile)) {
            // 读取练习文件
            java.util.Scanner scanner = new java.util.Scanner(file);
            int index = 1;
            while (scanner.hasNextLine()) {
                String line = scanner.nextLine();
                System.out.print(line);
                // 用户输入答案
                int answer = new java.util.Scanner(System.in).nextInt();
                // 检查答案是否正确
                boolean correct = checkAnswer(line, answer);
                String result = String.format("%d. %s %d\n", index, (correct ? "正确" : "错误"), answer);
                writer.write(result);
                writer.flush();
                index++;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static boolean checkAnswer(String exercise, int answer) {
        String[] parts = exercise.split(" ");
        int num1 = Integer.parseInt(parts[0]);
        String operator = parts[1];
        int num2 = Integer.parseInt(parts[2]);
        int result = (operator.equals("+")) ? (num1 + num2) : (num1 - num2);
        return (answer == result);
    }
}

该程序生成10道加法或减法的练习，将练习存储到文件`exercises.txt`中。用户可以在控制台中输入每道练习的答案，程序会检查答案是否正确，并将批改结果存储到文件`results.txt`中。