#include"SList_9_22.h"

void SListPrint(SL* phead)
{
	SL* cur = phead;
	while (cur)
	{
		printf("%d->", cur->data);
		cur = cur->next;
	}
	printf("NULL\n");
}
SL* BuySLNode(SL** pphead, SLDataType x)
{
	assert(pphead);
	SL* newnode = (SL*)malloc(sizeof(SL));
	if (newnode == NULL)
	{
		printf("malloc fail\n");
		exit(-1);
	}
	newnode->next = NULL;
	newnode->data = x;
	return newnode;
}
void SListPushBack(SL** pphead, SLDataType x)
{
	assert(pphead);
	SL* newnode = BuySLNode(pphead, x);
	if (*pphead == NULL)
	{
		*pphead = newnode;
	}
	else
	{
		SL* tail = *pphead;
		while (tail->next !=NULL)
		{
			tail = tail->next;
		}
		tail->next = newnode;
	}

}
void SListPopBack(SL** pphead)
{
	assert(pphead);
	assert(*pphead);
	if ((*pphead)->next == NULL)
	{
		free(*pphead);
		*pphead = NULL;
	}
	else
	{
		SL* prev = NULL;
		SL* cur = *pphead;
		while (cur->next != NULL)
		{
			prev = cur;
			cur = cur->next;
		}
		prev->next = NULL;
		free(cur);
	}
}
void SListPushFront(SL** pphead, SLDataType x)
{
	assert(pphead);
	SL* newnode = BuySLNode(pphead, x);
	newnode->next = *pphead;
	*pphead = newnode;

}
void SListPopFront(SL** pphead)
{
	assert(pphead);
	assert(*pphead);
	SL* prev = (*pphead)->next;
	free(*pphead);
	*pphead = prev;
}
SL* SListFind(SL* phead, SLDataType x)
{
	SL* cur = phead;
	while (cur->next != NULL)
	{
		if (cur->data == x)
		{
			return cur;
		}
		cur = cur->next;
	}
	return NULL;
}
void SListInsert(SL** pphead, SL* pos, SLDataType x)
{
	assert(pphead);
	assert(pos);
	SL* newnode = BuySLNode(pphead, x);
	if (*pphead == pos)
	{
		newnode->next = *pphead;
		*pphead = newnode;
	}
	else
	{
		SL* cur = *pphead;
		while (cur->next != pos)
		{
			cur = cur->next;
		}
		newnode->next = cur->next;
		cur->next = newnode;
	}
}
void SListInsertAfter(SL** pphead, SL* pos, SLDataType x)
{
	assert(pphead);
	assert(pos);
	SL* newnode = BuySLNode(pphead, x);
	newnode->next = pos->next;
	pos->next = newnode;
}
void SListEarse(SL** pphead, SL* pos)
{
	assert(pphead);
	assert(pos);
	if (*pphead == pos)
	{
		SL* cur = (*pphead)->next;
		free(*pphead);
		*pphead = cur;
	}
	else
	{
		SL* prev = *pphead;
		while (prev->next != pos)
		{
			prev = prev->next;
		}
		prev->next = pos->next;
		free(pos);
	}
}
void SListDestory(SL** pphead)
{
	assert(pphead);
	SL* prev = *pphead;
	while (prev->next != NULL)
	{
		SL* cur = prev->next;
		free(prev);
		prev = cur;
	}
	*pphead = NULL;
}