双向链表实现队列的 入队、出队、查找元素

typedef int DItemType;
typedef struct SDoubleList
{
	DItemType iValue;
	SDoubleList *prev;
	SDoubleList *next;

} DLinkedList,*pDLinkedList;

/* 创建双链表 */
DLinkedList *InitDoubleList()
{
	DLinkedList *doublelist = (DLinkedList*)malloc(sizeof(DLinkedList));
	if (NULL == doublelist)
		exit(1);
	doublelist->prev = NULL;
	doublelist->next = NULL;
	return doublelist;
}

/* 双链表实现队列入队 */
bool DLinkedList_Push(DLinkedList* DL, DItemType value)
{
	if (NULL==DL)
	{
		puts("队列不存在，无法插入！\n");
		return false;
	}
	DLinkedList *temp = (DLinkedList *)malloc(sizeof(DLinkedList));
	if (NULL == temp) {
		puts("插入失败！");
		return false;
	}
	temp->iValue = value;
	temp->next = NULL;
	temp->prev = NULL;

	DLinkedList *ttemp = DL;
	while (NULL != ttemp->next)
	{
		ttemp = ttemp->next;
	}
	ttemp->next = temp;
	temp->prev = ttemp;

	return true;
}

/* 双链表实现队列出队 */
bool DLinkedList_Pop(DLinkedList *DL)
{
	if (NULL==DL || NULL==DL->next) {
		puts("队列为空，无法出队！");
		return false;
	}

	DLinkedList *temp = DL->next;
	DL->next = temp->next;
	if (NULL==temp->next) {
		free(temp);
		return true;
	}
	temp->next->prev = DL;
	free(temp);

	return true;
}

/* 遍历队列 */
void VisitDLinkedList(DLinkedList *DL)
{
	if (NULL==DL || NULL == DL->next) {
		puts("队列为空！");
		return;
	}
	DLinkedList *temp = DL->next;
	while (NULL !=temp)
	{
		printf("%d ", temp->iValue);
		temp = temp->next;
	}
	printf("\n");
}

/* 查找某一元素 */
bool findItem(DLinkedList *DL, DItemType value)
{
	if (NULL==DL || NULL==DL->next) {
		puts("队列为空,查找失败！");
		return false;
	}
	DLinkedList *temp = DL->next;
	while (temp)
	{
		if (value==temp->iValue)
			return true;
		temp = temp->next;
	}
	return false;
}

void main()
{
	DLinkedList *DL;
	DL = InitDoubleList();
	DLinkedList_Push(DL, 10);
	DLinkedList_Push(DL, 20);
	DLinkedList_Push(DL, 30);

	VisitDLinkedList(DL);
	DLinkedList_Pop(DL);
	DLinkedList_Pop(DL);
	VisitDLinkedList(DL);
	if (findItem(DL,30))
		puts("查找成功！");
	else puts("查找失败！");

}