学步园

#include <iostream>
using namespace std;

//
struct IManager
{
public:
	IManager(IManager *pHighLevelManager) : m_pHighLevelManager(pHighLevelManager) { }
	virtual ~IManager() { }

	virtual void dealWithRequest(int num) = 0;

protected:
	IManager *m_pHighLevelManager;
};

class CCommonManager : public IManager
{
public:
	CCommonManager(IManager *pHighLevelManager) : IManager(pHighLevelManager) { }
	virtual ~CCommonManager() { }

	virtual void dealWithRequest(int num) 
	{
		if(num <= 500)
		{
			cout<<"common manager deal with request."<<endl;
		}
		else
		{
			m_pHighLevelManager->dealWithRequest(num);
		}
	}
};

class CMajorManager : public IManager
{
public:
	CMajorManager(IManager *pHighLevelManager) : IManager(pHighLevelManager) { }
	virtual ~CMajorManager() { }

	virtual void dealWithRequest(int num)
	{
		if(num <= 1000)
		{
			cout<<"major manager deal with request."<<endl;
		}
		else
		{
			m_pHighLevelManager->dealWithRequest(num);
		}
	}
};

class CTopManager : public IManager
{
public:
	CTopManager(IManager *pHighLevelManager) : IManager(pHighLevelManager) { }
	virtual ~CTopManager() { }

	virtual void dealWithRequest(int num)
	{
		cout<<"top manager deal with request."<<endl;
	}
};

//
void main()
{
	CTopManager topManager(NULL);
	CMajorManager majorManager(&topManager);
	CCommonManager commonManager(&majorManager);

	commonManager.dealWithRequest(300);
	commonManager.dealWithRequest(800);
	commonManager.dealWithRequest(3000);
}