数据结构之链表---双向链表(二)

七、在pos位置前面插入 

void LTInsert(LTNode* pos, LTDataType x)
{
	assert(pos);
	LTNode* posPrev = pos->prev;
	LTNode* newnode = CreateLTNode(x);

	posPrev->next = newnode;
	newnode->prev = posPrev;
	newnode->next = pos;
	pos->prev = newnode;
}

 

八、删除pos

void LTErase(LTNode* pos)
{
	assert(pos);

	LTNode* posNext = pos->next;
	LTNode* posPrev = pos->prev;

	posPrev->next = posNext;
	posNext->prev = posPrev;
	free(pos);
}