单向链表的C实现

单向链表：

/*结构体定义*/
#define  ERROR -1	
#define   OK   0  

typedef int DataType
typedef struct Node
{
   DataType  data;
   struct Node* next;
}Node,*PNODE;

/*初始化链表*/
void initList(PNODE *pHead)
{
	if (NULL == p_Head)
		return;
	
	*pHead = NULL;
}

PNODE newNode(DataType vData)
{
	PNODE newNode = NULL;
	newNode = (PNODE)malloc(sizeof(Node));
	if (NULL == newNode)
	{
		return ERROR;
	}
	else
	{
		newNode->data = vData;
		newNode->next = NULL;
	}
	
	return newNode;
}

void popBack(PNODE *pHead)//尾删
{
	if (NULL == pHead)
		return;

	if (NULL == *pHead)
		return;

	if (NULL == (*pHead)->next)//只有头结点，删除头结点，释放内存
	{
		PNODE tempnode = *pHead;
        free(tempnode);
		tempnode = NULL;
		*pHead = NULL;
	}
	else
	{
		PNODE curNode = *pHead;
		while(curNode->next->next)
		{
			curNode = curNode->next;
		}
		curNode->next = NULL;
	}
}

void pushBack(PNODE *pHead, DataType vData)//尾插
{
	if (NULL == pHead)
		return;
	
	if (NULL == *pHead)
	{
		*pHead = newNode(vData);
	}
	else
	{
		PNODE curNode = *pHead;
		
		while(curNode->next->next)
		{
			curNode = curNode->next;
		}
		curNode->next = newNode(vData);
	}

}

void popFront(PNODE *pHead)//头删
{
	if (NULL == pHead)
		return;
	
	if (NULL == *pHead)
	{
		return;
	}
	else if(NULL == (*pHead)->next)
	{
		*pHead = NULL;
	}
	else
	{
		PNODE preNode = *pHead;
		pHead = preNode->next;
		free(preNode);
		preNode = NULL;
	}

}

void pushFront(PNODE *pHead, DataType vData)//头插
{
	PNODE preNode  = NULL;
	PNODE tempNode = NULL;

	if (NULL == pHead)
		return;
	tempNode = newNode(vData);
	preNode  = *pHead;
	tempNode->next = preNode;
	*pHead = tempNode;
}

void insertList(PNODE pos, DataType vData)//data 后插入节点pos
{
	PNODE preNode  = NULL;
	PNODE tempNode = NULL;
	
	if (NULL == pos)
		return;
	preNode = pos;
	tempNode = newNode(vData);
	tempNode->next = preNode->next;
	preNode->next = tempNode;
}

参考：http://www.cnblogs.com/wft1990/p/6718623.html