//-----------------------------------------------------------------------------+
// Copyright (C), 1998-2007, Beijing Tangent Software Co. Ltd.
// = FileName	:   TPGeGList.h
// = Version	:   ver2.0
// = Author		:   xlc
// = CreateDate	:   2002-09-09
// = Description:   类的声明
// = Maintainers: cpp中176行的temp变量没有声明，如何编译？
//                  
//-----------------------------------------------------------------------------+
#ifndef _TPGEGLIST_H_
#define _TPGEGLIST_H_

//递归链或图链，方便链动态组建和链高级操作
//每个链结点都代表和管理由本结点和后续链组成的链。
template<class T> class TPGeGList
{
public:

	//构造
	TPGeGList();
	
	//析构,有后续子环路时不能调用下列函数!!!
	virtual ~TPGeGList();

	virtual void DCNNext();
	
	virtual void CNNext(TPGeGList* pList);
	
	//数据
	const T& GetData()const;
	
	const T& GetData(long i)const;
	
	T& Data();

	T& Data(long i);
	
	//释放所有后续结点,本结点成为终止结点
	void ReleaseAll();

	//链接
	void SetNext(TPGeGList<T>* pList);
	//插入合并
	void InsertNext(TPGeGList<T>* pList);
	
	//摘取长度为num的后续子链,，num must be >0 and valid!!!
	TPGeGList<T>* FetchNext(long num = 1);

	//删除长度为num的后续子链
	void DelNext(long num = 1);

	//遍历,有后续子环路时不能调用下列函数!!
	long Length()const;

	TPGeGList<T>* Next()const;

	TPGeGList<T>* GetAt(long i)const;

	TPGeGList<T>* GetTail()const;

	bool IsClosed()const;
	
	//返回新链首,如果本结点非链首，将在本结点处形成分叉!如果是环路将保持环路
	TPGeGList<T>* Reverse();

	const TPGeGList* Find(T&t)const;
	
protected:

	T data;

	TPGeGList *next;
};

template<class T>
TPGeGList<T>::TPGeGList()
: next(NULL)
{

}

template<class T>
TPGeGList<T>::~TPGeGList()
{
	//析构时需保证前链接已经断开!!
	ReleaseAll();
}

template<class T>
const T& TPGeGList<T>::GetData() const
{
	return data;
}

template<class T>
T& TPGeGList<T>::Data()
{
	return data;
}

template<class T>
const T& TPGeGList<T>::GetData(long i) const
{
	return GetAt(i)->GetData();
}

template<class T>
T& TPGeGList<T>::Data(long i)
{
	return GetAt(i)->Data();
}

template<class T>
void TPGeGList<T>::SetNext(TPGeGList<T>*pList)
{
	next = pList;
}

template<class T>
void TPGeGList<T>::CNNext(TPGeGList*pList)
{
	next = pList;
}


template<class T>
void TPGeGList<T>::DCNNext()
{
	next = NULL;
}

template<class T>
void TPGeGList<T>::DelNext(long num/* = 1*/)
{
	delete FetchNext(num);
}

template<class T>
TPGeGList<T>* TPGeGList<T>::Next() const
{
	return next;
}

template<class T>
bool TPGeGList<T>::IsClosed() const
{
	return GetTail()->Next() == this;
}


template<class T>
const TPGeGList<T>* TPGeGList<T>::Find(T&t) const
{
	if (data == t)
	{
		return this;
	}

	for (const TPGeGList* p = Next();p != NULL && p != this;p = p->Next())
	{
		if (p->GetData() == t)
		{
			return p;
		}
	}

	return NULL;
}

template<class T>
TPGeGList<T>* TPGeGList<T>::Reverse()
{
	TPGeGList<T> *pPre = this,*pCur = Next();
	while(pCur != NULL && pCur != this)
	{
		TPGeGList<T>* temp = pCur->Next();
		pCur->SetNext(pPre);
		pPre = pCur;
		pCur = temp;
	}
	if (pCur == NULL)
	{
		SetNext(NULL);
		return pPre;
	}
	else
	{
		SetNext(pPre);
		return this;
	}	
}

template<class T>
long TPGeGList<T>::Length() const
{
	long count = 1;
	for (TPGeGList*pCur = Next();pCur != NULL && pCur != this;pCur = pCur->Next())
	{
		count++;
	}
	return count;
}

template<class T>
TPGeGList<T>* TPGeGList<T>::GetAt(long i) const
{
	const TPGeGList<T>*pCur = this;
	for (long j = 0;j<i && pCur != NULL;j++,pCur = pCur->Next());
	return (TPGeGList<T>*)pCur;
}

template<class T>
TPGeGList<T>* TPGeGList<T>::GetTail() const
{
	const TPGeGList<T>*pCur;
	for (pCur = this;pCur->Next() != this && pCur->Next() != NULL;pCur = pCur->Next());
	return (TPGeGList<T>*)pCur;
}

template<class T>
void TPGeGList<T>::InsertNext(TPGeGList<T>*pList)
{
	TPGeGList<T>*pOldNext = Next();
	CNNext(pList);
	if (pOldNext != NULL)
	{
		pList->GetTail()->CNNext(pOldNext);
	}
}

template<class T>
TPGeGList<T>* TPGeGList<T>::FetchNext(long num)
{
	TPGeGList<T>*pOldNext = Next();
	TPGeGList<T>*pLast = GetAt(num);
	TPGeGList<T>*pTemp = pLast->Next();
	if (pTemp != NULL)
	{
		pLast->DCNNext();
		CNNext(pTemp);
	}
	return pOldNext;	
}

template<class T>
void TPGeGList<T>::ReleaseAll()
{
	for (TPGeGList<T> *pCur = Next();pCur != NULL && pCur != this;)
	{
		TPGeGList<T>*temp = pCur->Next();
		pCur->SetNext(NULL);
		delete pCur;
		pCur = temp;
	}
	SetNext(NULL);
}

#endif