[C++] 템플릿을 이용한 Linked List 구현

2019.09.01 직접구현 (오류가 있을 수 있음)

template<typename T> struct CNode
{
	CNode(T _value)
	{
		value = _value;
	}
	CNode* next;
	CNode* prev;
	T value;
};

template<typename T> class CLinkedList
{
private:
	
	CNode<T>* head;
	CNode<T>* tail;
	int count;

public:
	CLinkedList() : head(NULL), tail(NULL), count(0) 
	{
	}
	~CLinkedList()
	{
		clear();
	}

public:
	int add(T item)
	{
		CNode<T> *newNode = new CNode<T>(item);
		if (count == 0)
		{
			head = newNode;
			tail = newNode;
			newNode->next = NULL;
			newNode->prev = NULL;
		}
		else
		{
			newNode->next = NULL;
			newNode->prev = tail;
			tail->next = newNode;
			tail = newNode;
		}
		++count;

		return count;
	}

	int erase(T item)
	{
		CNode<T> *pThis = head;
		while (pThis)
		{
			if (pThis->value == item)
			{
				if (pThis->prev) 
				{
					pThis->prev->next = pThis->next;					
				}
				else // prev 가 없다는건 head 를 삭제하는것이므로 다음것을 head 로 임명
				{
					head = pThis->next;
				}
				if (pThis->next)
				{
					pThis->next->prev = pThis->prev;
				}
				else // next 가 없다는건 tail 을 삭제하는것이므로 이전것을 tail 로 임명
				{
					tail = pThis->prev;
				}
				delete pThis;
				--count;
				break;
			}
			pThis = pThis->next;
		}
		return count;
	}

	void clear()
	{
		CNode<T> *pThis = head;
		while (pThis)
		{			
			CNode<T> *pDelete = pThis;

			if (pThis->prev)
				pThis->prev->next = pThis->next;
			if (pThis->next)
				pThis->next->prev = pThis->prev;

			pThis = pThis->next;

			delete pDelete;			
			--count;
		}
		head = NULL;
		tail = NULL;
	}

	int getSize()
	{
		return count;
	}
	void printAll()
	{
		if (count > 0)
		{
			CNode<T> *pThis = head;
			while (pThis)
			{
				cout << pThis->value << endl;
				pThis = pThis->next;
			}
		}
	}

	CNode<T>* getHead() { return head;  }
	CNode<T>* getTail() { return tail;  }

};

 

아래는 사용예

int main(int argc, char* argv[])
{
	CLinkedList<int> list;
	list.add(10);
	list.add(20);
	list.add(30);

	list.erase(10);

	list.printAll();

	list.clear();
	
	list.printAll();

	_CrtDumpMemoryLeaks();

	return 0;
}