java习题生成50道100以内加减法混和习题，题中不能有相同的算式,加法和减法生成模块进行分离（更改）

在Java中生成50道100以内随机的加减混合运算习题，你可以创建两个独立的模块，分别负责生成加法和减法题目。这里是一个简单的示例：

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

// 加法生成模块
public class AdditionGenerator {
    private static final int MAX_VALUE = 100;
    public List<String> generate(int numQuestions) {
        List<String> questions = new ArrayList<>();
        for (int i = 0; i < numQuestions; i++) {
            int a = (int) (Math.random() * MAX_VALUE);
            int b = (int) (Math.random() * MAX_VALUE);
            while (a == b || questions.contains(a + " + " + b)) { // 确保不重复
                b = (int) (Math.random() * MAX_VALUE);
            }
            questions.add(String.format("%d + %d", a, b));
        }
        return questions;
    }
}

// 减法生成模块
public class SubtractionGenerator {
    private static final int MAX_VALUE = 100;
    public List<String> generate(int numQuestions) {
        List<String> questions = new ArrayList<>();
        for (int i = 0; i < numQuestions; i++) {
            int a = (int) (Math.random() * MAX_VALUE);
            int b = (int) (Math.random() * MAX_VALUE);
            while (a == b || questions.contains(String.format("%d - %d", a, b))) { // 确保不重复
                b = (int) (Math.random() * MAX_VALUE);
            }
            questions.add(String.format("%d - %d", a, b));
        }
        return questions;
    }
}

然后，你可以结合这两个模块来生成混合的习题集：

public class Main {
    public static void main(String[] args) {
        int totalQuestions = 50;
        AdditionGenerator addGen = new AdditionGenerator();
        SubtractionGenerator subGen = new SubtractionGenerator();

        List<String> additionQuestions = addGen.generate(totalQuestions / 2);
        List<String> subtractionQuestions = subGen.generate(totalQuestions / 2);

        List<String> mixedQuestions = new ArrayList<>(additionQuestions);
        mixedQuestions.addAll(subtractionQuestions);
        Collections.shuffle(mixedQuestions); // 随机排序

        System.out.println("混合习题集:");
        for (String question : mixedQuestions) {
            System.out.println(question);
        }
    }
}

这将生成包含50道加减混合题目的列表，其中加法和减法各占一半，且每个算式都是唯一的。