数据结构_单链表基本操作

 关于单链表的一些基本操作，包括头插，尾插，头删，尾删等等

#include <stdlib.h>
#include <assert.h>
#include <stdio.h>

typedef int DataType;

typedef struct SListNode
{
	DataType data;
	struct SListNode *pNext;
} SListNode;


//申请新空间
SListNode *__CreatNewNode(DataType data)
{
	SListNode *pNewNode = (SListNode *)malloc(sizeof(SListNode));
	assert(pNewNode);

	pNewNode->data = data;
	pNewNode->pNext = NULL;

	return pNewNode;
}


//打印函数
void SListNodePrint(SListNode **ppfirst)
{
	SListNode *pNode;
	for (pNode = *ppfirst; pNode != NULL; pNode = pNode->pNext)
	{
		printf("%d -> ", pNode->data);
	}
	printf("NULL\n");
}

void SListPushBack(SListNode **ppfirst, DataType data);
void SListPushFront(SListNode **ppfirst, DataType data);
void SListPopBack(SListNode **ppfirst);
void SListPopFront(SListNode **ppfirst);
void SListInsert(SListNode **ppfirst,SListNode *pos, DataType data);
void SListErase(SListNode **ppfirst,SListNode *pos);
void SListRemove(SListNode **ppfirst, DataType data);
void SListRemoveAll(SListNode **ppfirst, DataType data);

//初始化
void SListNodeInit(SListNode **ppfirst)
{
	*ppfirst = NULL;
}


//尾插
void SListPushBack(SListNode **ppfirst, DataType data)
{
	SListNode *pNewNode = __CreatNewNode(data);
	SListNode *pNode;
	if (*ppfirst == NULL)
	{
		*ppfirst = pNewNode;
		return;
	}
	for (pNode = *ppfirst; pNode->pNext != NULL; pNode = pNode->pNext)
	{}
	pNode->pNext = pNewNode;
}


//头插
void SListPushFront(SListNode **ppfirst, DataType data)
{
	SListNode *pNewNode = __CreatNewNode(data);
	if (*ppfirst == NULL)
	{
		*ppfirst = pNewNode;
		return;
	}
	pNewNode->pNext = *ppfirst;
	*ppfirst = pNewNode;
}


//尾删
void SListPopBack(SListNode **ppfirst)
{
	SListNode *pNode;
	SListNode *pDel;
	if (*ppfirst == NULL)
	{
		return;
	}

	if ((*ppfirst)->pNext == NULL)
	{
		free(*ppfirst);
		return;
	}
	for (pNode = *ppfirst; pNode->pNext->pNext != NULL; pNode = pNode->pNext)
	{

	}
	pDel = pNode->pNext;
	pNode->pNext = NULL;
	free(pDel);
}


//头删
void SListPopFront(SListNode **ppfirst)
{
	SListNode *pNode;
	if (*ppfirst == NULL)
	{
		return;
	}
	if ((*ppfirst)->pNext == NULL)
	{
		free(*ppfirst);
		return;
	}
	pNode = *ppfirst;
	*ppfirst = pNode->pNext;
	free(pNode);
}


//查找函数
SListNode *Find(SListNode **ppfirst, DataType data)
{
	SListNode *pNode;
	for (pNode = *ppfirst; pNode != NULL; pNode = pNode->pNext)
	{
		if (pNode->data == data)
			return pNode;
	}
	return NULL;
}


//中间插
void SListInsert(SListNode **ppfirst, SListNode *pos, DataType data)
{
	assert(*ppfirst);
	SListNode *pNewNode = __CreatNewNode(data);
	SListNode *pNode;
	if (*ppfirst == NULL)
	{
		*ppfirst = pNewNode;
		return;
	}
	if (*ppfirst == pos)
	{
		SListPushFront(ppfirst,data);
		return;
	}
	for (pNode = *ppfirst; pNode->pNext != pos; pNode = pNode->pNext)
	{

	}
	pNode->pNext = pNewNode;
	pNewNode->pNext = pos;
}

//中间删
void SListErase(SListNode **ppfirst,SListNode *pos)
{
	assert(*ppfirst);
	SListNode *pNode;
	for (pNode = *ppfirst; pNode->pNext != pos; pNode = pNode->pNext)
	{

	}
	pNode->pNext = pos->pNext;
	free(pos);
}



//按值删
void SListRemove(SListNode **ppfirst, DataType data)
{
	assert(*ppfirst);
	SListNode *pNode=Find(ppfirst,data);
	assert(pNode);
	SListErase(ppfirst, pNode);


}


//按值删所有
void SListRemoveAll(SListNode **ppfirst, DataType data)
{
	assert(*ppfirst);
	SListNode *pNode=*ppfirst;
	SListNode *pCmp;
	while (pNode->pNext != NULL)
	{
		pCmp = pNode->pNext;
		if (pCmp->data == data)
		{
			pNode->pNext = pCmp->pNext;
			free(pCmp);
		}
		else
		{
			pNode = pNode->pNext;
		}
	}
	if ((*ppfirst)->data == data)
	{
		pNode = *ppfirst;
		*ppfirst = (*ppfirst)->pNext;
		free(pNode);
	}
}


//销毁
void SListDestroy(SListNode **ppfirst)
{
	assert(*ppfirst);
	SListNode *pNode;
	SListNode  *pN;
	for (pNode = *ppfirst; pNode != NULL;)
	{
		pN = pNode;
		pNode = pNode->pNext;
		free(pN);
	}
}