这个程序该怎么完成啊

12.2、声明一个基类OBJ，该基类保护成员m_Name，由此派生出立方体和球体的派生类分别为CUBE和SPHERE，立方体的成员为边长m_R，球体的成员为半径m_Radial，在程序中初始化一个立方体和球体的对象，并将立方体边长设置为3.2，球体半径设置为3.5，并使用基类的指针，通过动态绑定到之前的立方体和球体的对象，使用该基类指针访问并输出立方体和球体的体积。

#include <iostream>
#include <cmath>
#include <stdexcept>
#include <memory>

class OBJ
{
public:
    OBJ(const std::string &name) : m_Name(name) {}
    virtual ~OBJ() = default;

    virtual float volume() const = 0;

    const std::string getName() const { return m_Name; }
    void setName(const std::string &name) { m_Name = name; }

protected:
    std::string m_Name;
};

class CUBE : public OBJ
{
public:
    CUBE(const std::string &name, float r) : OBJ(name), m_R(r)
    {
        if (r <= 0.0f)
            throw std::invalid_argument("invalid cube");
    }

    float getR() const { return m_R; }
    void setR(float r) { m_R = r; }

    virtual float volume() const { return std::pow(m_R, 3); }

private:
    float m_R;
};

class SPHERE : public OBJ
{
public:
    SPHERE(const std::string &name, float r) : OBJ(name), m_Radial(r)
    {
        if (r <= 0.0f)
            throw std::invalid_argument("invalid sphere");
    }

    float getRadial() const { return m_Radial; }
    void setRadial(float r) { m_Radial = r; }

    virtual float volume() const { return static_cast<float>(std::pow(m_Radial, 3) * M_PI * 4.0 / 3.0); }

private:
    float m_Radial;
};

int main()
{
    OBJ *p1 = new CUBE("cube1", 3.2f);
    OBJ *p2 = new SPHERE("sphere1", 3.5f);
    std::cout << p1->getName() << "'s volume is " << p1->volume() << '\n';
    std::cout << p2->getName() << "'s volume is " << p2->volume() << '\n';
    delete p1;
    delete p2;
    return 0;
}