双向链表的C实现.doc

双向链表的C实现struct Node void* pUserData;struct Node* pNext;struct Node* pPrev; _Node;struct TABLE struct Node* pHead;struct Node* pTail; _TABLE;struct POSITION struct TABLE* pTable; struct Node* pNode; _POSITION;struct TABLE* CreateTable(void);void FreeTable(struct TABLE*);void AddTail(struct TABLE*,void* pUserData);void InsertAt(struct POSITION*,void*);void RemoveAt(struct POSITION*);void* GetAt(struct POSITION*);void* GetNext(struct POSITION*);void* GetPrev(struct POSITION*);struct POSITION GetHeadPosition(struct TABLE*);struct POSITION GetTailPosition(struct TABLE*);struct POSITION GetPosition(struct TABLE*,unsigned int);int GetCount(struct TABLE*);struct TABLE* CreateTable()struct TABLE* pTable = (struct TABLE*)malloc(sizeof(_TABLE);if(pTable = NULL)return NULL;pTable- pHead = NULL;pTable- pTail = NULL;return pTable;void FreeTable(struct TABLE* pTable)struct Node* pNode;while(pTable- pHead)pNode = pTable- pHead;pTable- pHead = pTable- pHead- pNext;free(pNode);free(pTable);void AddTail(struct TABLE* pTable,void* pUserData)struct Node* pNode;pNode = (struct Node*)malloc(sizeof(_Node);if(pNode = NULL)return;pNode- pUserData = pUserData;pNode- pNext = NULL;if(pTable- pHead=NULL & pTable- pTail=NULL)pNode- pPrev = NULL;pTable- pHead = pNode;elsepNode- pPrev = pTable- pTail;pTable- pTail- pNext = pNode;pTable- pTail = pNode;void RemoveAt(struct POSITION* pos)if(pos- pNode = NULL)errcode|=1 pTable- pHead = NULL & pos- pTable- pTail = NULL)return;if(pos- pNode = pos- pTable- pHead)if(pos- pNode = pos- pTable- pTail)pos- pTable- pHead = NULL;pos- pTable- pTail = NULL;elsepos- pTable- pHead = pos- pNode- pNext;pos- pTable- pHead- pPrev = NULL;elseif(pos- pNode = pos- pTable- pTail)pos- pTable- pTail = pos- pNode- pPrev;pos- pTable- pTail- pNext = NULL;elsepos- pNode- pPrev- pNext = pos- pNode- pNext;pos- pNode- pNext- pPrev = pos- pNode- pPrev;free(pos- pNode);void InsertAt(struct POSITION* pos,void* pUserData)struct Node* pNode;if(pos- pNode = NULL)return;pNode = (struct Node*)malloc(sizeof(_Node);if(pNode = NULL)return;pNode- pUserData = pUserData;if(pos- pNode = pos- pTable- pHead)pNode- pPrev = NULL;pNode- pNext = pos- pTable- pHead;pos- pTable- pHead- pPrev = pNode;pos- pTable- pHead = pNode;elsepos- pNode- pPrev- pNext = pNode;pNode- pPrev = pos- pNode- pPrev;pNode- pNext = pos- pNode;pos- pNode- pPrev = pNode;void* GetAt(struct POSITION* pos)if(pos- pNode = NULL)return NULL;return pos- pNode- pUserData;void* GetNext(struct POSITION* pos)struct Node* pNode;if(pos- pNode = NULL) return NULL;pNode = pos- pNode;pos- pNode = pos- pNode- pNext;return pNode- pUserData;void* GetPrev(struct POSITION* pos)struct Node* pNode;if(pos- pNode = NULL) return NULL;pNode = pos- pNode;pos- pNode = pos- pNode- pPrev;return pNode- pUserData;struct POSITION GetHeadPosition(struct TABLE* pTable)struct POSITION pos;pos.pTable = pTable;pos.pNode = pTable- pHead;return pos;struct POSITION GetTailPosition(struct TABLE* pTable)struct POSITION pos;pos.pTable = pTable;pos.pNode = pTable- pTail;return pos;struct POSITION GetPosition(struct TABLE* pTable,unsigned int index)struct POSITION pos;pos.pTable = pTable;pos.pNode = pTable- pHead;while(index-)if(pos.pNode = NULL)break;pos.pNode = p