數據結構：雙向鏈表的c語言實現

dlinklist.h

#ifndef _DLINKLIST_H_
#define _DLINKLIST_H_
#include<stdio.h>



typedef void DLinkList;

typedef struct _tag_DLinkListNode
{
	struct _tag_DLinkListNode* next;
	struct _tag_DLinkListNode* pre;
}DLinkListNode;

DLinkList* DLinkList_Create();
void DLinkList_Destroy(DLinkList* list);
void DLinkList_Clear(DLinkList* list);
int DLinkList_Length(DLinkList* list);

int DLinkList_Insert(DLinkList* list, DLinkListNode* node, int pos);
DLinkListNode* DLinkList_Get(DLinkList* list, int pos);
DLinkListNode* DLinkList_Delete(DLinkList*list, int pos);
DLinkListNode* DLinkList_DeleteNode(DLinkList*list, DLinkListNode* node);

DLinkListNode* DLinkList_Reset(DLinkList* list);
DLinkListNode* DLinkList_Current(DLinkList*list);
DLinkListNode* DLinkList_Next(DLinkList*list);
DLinkListNode* DLinkList_Pre(DLinkList*list);

#endif // !_DLINKLIST_H_

鏈表結點中有next指針和pre指針

dlinklist.c

#include "DLinkList.h"
#include<malloc.h>

typedef struct _tag_DLinkList
{

	DLinkListNode	header;
	DLinkListNode*  slider;
	int length;

}TDLinkList;

DLinkList* DLinkList_Create()
{
	TDLinkList * ret = (TDLinkList*)malloc(sizeof(TDLinkList));

	if (ret != NULL)
	{
		ret->length = 0;
		ret->header.next = NULL;
		ret->header.pre = NULL;
		ret->slider = NULL;
	}
	return ret;
}

void DLinkList_Destroy(DLinkList* list)
{
	if (list != NULL)
	{
		free(list);
	}
}

void DLinkList_Clear(DLinkList* list)
{
	TDLinkList* sList = (TDLinkList*)list;

	if (sList != NULL)
	{
		sList->length = 0;
		sList->header.next = NULL;
		sList->header.pre = NULL;
		sList->slider = NULL;
	}
}

int DLinkList_Length(DLinkList *list)
{
	TDLinkList *sList = (TDLinkList*)list;
	int ret = -1;

	if (sList != NULL)
	{
		ret = sList->length;
	}
	return ret;
}

int DLinkList_Insert(DLinkList* list, DLinkListNode* node, int pos)
{
	int ret = 0, i = 0;
	TDLinkList *sList = (TDLinkList*)list;

	if (list == NULL || node == NULL || pos < 0)
	{
		return -1;
	}
	{
		DLinkListNode* current = (DLinkListNode*)sList;
		DLinkListNode* next = NULL;

		for (i = 0; (i < pos) && (current->next != NULL); i++)
		{
			current = current->next;
		}
		next = current->next;

		current->next = node;
		node->next = next;

		if (next != NULL)//當鏈表插入第一個元素，需要特殊處理
		{
			next->pre = node;
		}
		node->pre = current;

		if (sList->length == 0)
		{
			sList->slider = node;
		}
		//若在0位置插入，需要特殊處理，新來結點pre 指向null
		if (current == (DLinkListNode*)sList)
		{
			node->pre = NULL;
		}
		sList->length++;
	}
	return ret;
}

DLinkListNode* DLinkList_Get(DLinkList* list, int pos)
{
	TDLinkList *sList = (TDLinkList*)list;
	DLinkListNode* ret = NULL;
	int i = 0;

	if ((sList != NULL) && (0 <= pos) && (pos < sList->length))
	{
		DLinkListNode* current = (DLinkListNode*)sList;

		for (i = 0; i < pos; i++)
		{
			current = current->next;
		}
		ret = current->next;
	}
	return ret;
}

//插入第一個節點，刪除的是最後一個節點，該如何處理
DLinkListNode* DLinkList_Delete(DLinkList* list,int pos)
{
	TDLinkList* sList = (TDLinkList*)list;
	DLinkListNode* ret = NULL;
	int i = 0;
	if ((sList == NULL) || pos < 0)
	{
		return NULL;

	}
	{
		DLinkListNode* current = (DLinkListNode*)sList;
		DLinkListNode* next = NULL;

		for (i = 0; i < pos; i++)
		{
			current = current->next;
		}

		ret = current->next;
		next = ret->next;

		current->next = next;

		if (next != NULL)
		{
			next->pre = current;
			if (current == (DLinkListNode*)sList)
			{
				next->pre = NULL;
			}
		}
		if (sList->slider == ret)
		{
			sList->slider = next;
		}

		sList->length--;
	}
	return ret;
}

DLinkListNode* DLinkList_DeleteNode(DLinkList* list, DLinkListNode* node)
{
	TDLinkList* sList = (TDLinkList*)list;
	DLinkListNode* ret = NULL;
	int i = 0;

	if (sList != NULL)
	{
		DLinkListNode* current = (DLinkListNode*)sList;
		for (i = 0; i < sList->length; i++)
		{
			if (current->next == node)
			{
				ret = current->next;
				break;
			}
			current = current->next;
		}
		if (ret != NULL)
		{
			DLinkList_Delete(sList, i);
		}
	}
	return ret;
}

DLinkListNode* DLinkList_Reset(DLinkList* list)
{
	TDLinkList *sList = (TDLinkList*)list;
	DLinkListNode* ret = NULL;

	if (sList != NULL)
	{
		sList->slider = sList->header.next;
		ret = sList->slider;
	}
	return ret;
}

DLinkListNode* DLinkList_Current(DLinkList* list)
{
	TDLinkList *sList = (TDLinkList*)list;
	DLinkListNode *ret = NULL;

	if (sList != NULL)
	{
		ret = sList->slider;
	}
	return ret;
}
DLinkListNode* DLinkList_Pre(DLinkList* list)
{
	TDLinkList* sList = (TDLinkList*)list;
	DLinkListNode* ret = NULL;
	if ((sList != NULL) && (sList->slider != NULL))
	{
		ret = sList->slider;
		sList->slider = ret->pre;
	}
	return ret;
}

DLinkListNode* DLinkList_Next(DLinkList* list)
{
	TDLinkList *sList = (TDLinkList*)list;
	DLinkListNode *ret = NULL;

	if ((sList != NULL) && (sList->slider != NULL))
	{
		ret = sList->slider;
		sList->slider = ret->next;
	}
	return ret;
}