定义：策略模式定义了一系列的算法，并将每一个算法封装起来，而且使它们还可以相互替换。策略模式让算法独立于使用它的客户而独立变化。

class Light{
public:
    void on()
    {
        cout << "Light on !" << endl;
    }

    void off()
    {
        cout << "Light off !" << endl;
    }
};
//命令类
class Command{
public:
    virtual ~Command(){}
    virtual void execute(){}
};
//具体命令类
class LigthOnCommand : public Command
{
public:
    LigthOnCommand(Light* lig):light(lig){}
    //execute方法
    void execute()
    {
        light->on();
    }
private:
    Light *light;
};
class LigthOffCommand : public Command{
public:
    LigthOffCommand(Light *lig):light(lig){}
    //execute方法
    void execute()
    {
        light->off();
    }
private:
    Light *light;
};
//遥控器类
class RemoteControl{
public:
    void SetCommand(Command *cmd)
    {
        slot = cmd;
    }
    void buttonOn()
    {
        slot->execute();
    }
private:
    Command *slot;
};

int main()
{
    RemoteControl lightOnControl;
    RemoteControl lightOffControl;
    Command *onCommand = new LigthOnCommand(new Light());
    Command *offCommand = new LigthOffCommand(new Light());
    lightOnControl.SetCommand(onCommand);
    lightOffControl.SetCommand(offCommand);
    lightOnControl.buttonOn();
    lightOffControl.buttonOn();

}