试着写出所能想象的所有形状，生成一个形状层次类结构，生成的类结构以shape作为基类，并由此生出Twodimshape类和Threedimshape类，他们的派生类是不同形状类，定义层次结构中每一个类并用main函数测试。用c++写

在C++中，我们可以创建一个简单的形状层次类结构，包括基础形状、二维形状和三维形状。首先，我们从`Shape`基类开始，然后创建派生类如`Circle`, `Square`等属于二维形状，以及`Cube`, `Sphere`等属于三维形状。以下是一个简化的示例：

#include <iostream>
#include <string>

// 基础形状
class Shape {
public:
    virtual ~Shape() {}
    virtual std::string getDimension() const = 0; // 获取形状维度
    virtual void display() const = 0; // 展示形状信息
};

// 二维形状
class Twodimshape : public Shape {
protected:
    std::string shapeType;
public:
    Twodimshape(const std::string& type) : shapeType(type) {}
    std::string getDimension() const override { return "Two-dimensional"; }
    virtual void display() const override {
        std::cout << "This is a " << shapeType << " shape." << std::endl;
    }
};

// 具体的二维形状例子，比如圆形和正方形
class Circle : public Twodimshape {
public:
    Circle(double radius) : Twodimshape("Circle"), radius(radius) {}
    double radius;
    void display() const override {
        Twodimshape::display();
        std::cout << "Radius: " << radius << std::endl;
    }
};

class Square : public Twodimshape {
public:
    Square(int side) : Twodimshape("Square"), side(side) {}
    int side;
    void display() const override {
        Twodimshape::display();
        std::cout << "Side length: " << side << std::endl;
    }
};

// 三维形状
class Threedimshape : public Shape {
protected:
    std::string shapeType;
public:
    Threedimshape(const std::string& type) : shapeType(type) {}
    std::string getDimension() const override { return "Three-dimensional"; }
    virtual void display() const override {
        std::cout << "This is a " << shapeType << " shape." << std::endl;
    }
};

// 具体的三维形状例子，比如立方体和球体
class Cube : public Threedimshape {
public:
    Cube(double edgeLength) : Threedimshape("Cube"), edgeLength(edgeLength) {}
    double edgeLength;
    void display() const override {
        Threedimshape::display();
        std::cout << "Edge length: " << edgeLength << std::endl;
    }
};

class Sphere : public Threedimshape {
public:
    Sphere(double radius) : Threedimshape("Sphere"), radius(radius) {}
    double radius;
    void display() const override {
        Threedimshape::display();
        std::cout << "Radius: " << radius << std::endl;
    }
};

int main() {
    Circle circle(5);
    square Square(4);
    Cube cube(3);
    Sphere sphere(2);

    circle.display();
    square.display();
    cube.display();
    sphere.display();

    return 0;
}

在这个例子中，`main()`函数中展示了每个形状的实例，并通过`display()`方法展示其信息。