双向链表之插入

// Double Linked List
typedef struct Node{
	int value;
	Node *next;
	Node *prev;
}Node;

Node *doubleLink_Insert(Node *pHead, int value)
{
	// New
	Node *newNode = (Node *)malloc(sizeof(Node));
	newNode->value = value;
	newNode->next = NULL;
	newNode->prev = NULL;

    // Head is null
	if (pHead == NULL)
	{
		pHead = newNode;
		return pHead;
	}

	// Insert front
	if (pHead->value >= value)
	{
		newNode->next = pHead;
		pHead->prev = newNode;
		pHead = newNode;
		return pHead;
	}
	Node *temp = pHead;
	// 方法一 与方法二效果相同，但这里只会在temp后面进行插入
	while(temp->next != NULL && temp->next->value < value)
	{
		temp = temp->next;
	}

	if (temp->next == NULL)
	{
		temp->next = newNode;
		newNode->prev = temp;
	}
	else
	{
		newNode->next = temp->next;
		newNode->prev = temp;
		temp->next->prev = newNode;
		temp = newNode;
	}
    return pHead;

    #ifdef TEST
    // 方法二 
	while (temp != NULL)
	{
		if (temp->value <= value)
		{
			if(temp->next != NULL)
				temp = temp->next;
			else
			{
                //Insert back 在temp的后面插入
				temp->next = newNode;
				newNode->prev = temp;
				return pHead;
			}
		}
		else
		{
            // insert front 在temp之前插入
			newNode->next = temp;
			newNode->prev = temp->prev;
			temp->prev->next = newNode;
			temp->prev = newNode;
			return pHead;
		}
	}
	#endif
}

int main()
{
     int data[MAX_SIZE] = {5, 4, 3, 2, 1};//{0, 0, 1, 4, 5, 5, 7, 8, 10, 9};
     char sizeofT[] = "a";
     examSinfor(sizeofT);
     int length = 0;
     Node *pHead = NULL;
     for (int i = 0; i < 15; ++i)
     {
     	pHead = doubleLink_Insert(pHead, i);
     }
     for (int j = 0; j < 15; ++j)
     {
     	pHead = doubleLink_Insert(pHead, j);				
     }
     //pHead = doubleLink_Insert(pHead, 2);
     Node *temp = pHead;
     while (temp)
     {
     	cout << temp->value << " ";
     	temp = temp->next;
     }
    return 0;
}