class Computer
{
public:
    virtual void Run() = 0;
    virtual void Stop() = 0;
};
class Laptop: public Computer
{
public:
    virtual void Run(){mHibernating = false;}
    virtual void Stop(){mHibernating = true;}
private:
    bool mHibernating; // Whether or not the machine is hibernating
};
class Desktop: public Computer
{
public:
    virtual void Run(){mOn = true;}
    virtual void Stop(){mOn = false;}
private:
    bool mOn; // Whether or not the machine has been turned on
};
 
class ComputerFactory
{
public:
    static Computer *NewComputer(const std::string &description)
    {
        if(description == "laptop")
            return new Laptop;
        if(description == "desktop")
            return new Desktop;
        return NULL;
    }
};