剑指offer面试题35：复杂链表的复制

题目：请实现函数ComplexListNode* Clone(ComplexListNode* pHead),复制一个复杂链表。在复杂链表中，每个节点除了有一个m_pNext指针指向下一个节点，还有一个m_pSlbling指针指向链表的任意节点或者nullptr。

思路：
方案一：哈希表（需要O(N)的辅助空间）
方案二：第一步，复制链表节点连接在被复制节点后；第二步，复制m_pSibling指针；第三步，拆分链表即可。

struct ComplexListNode {
	int             m_nValue;
	ComplexListNode *m_pNext;
	ComplexListNode *m_pSibling;
};

void CloneNodes(ComplexListNode *pHead) {
	if (NULL == pHead) {
		return;
	}

	ComplexListNode *pNode = pHead;
	while (pNode != NULL) {
		// create new node
		ComplexListNode *tmp = (ComplexListNode *)calloc(1, sizeof(ComplexListNode));
		tmp->m_nValue = pNode->m_nValue;
		tmp->m_pNext = pNode->m_pNext;
		tmp->m_pSibling = NULL;

		pNode->m_pNext = tmp;
		pNode = tmp->m_pNext;
	}
}

void ConnectSiblingNodes(ComplexListNode *pHead) {
	if (NULL == pHead) {
		return;
	}
	ComplexListNode *pNode = pHead;
	while (pNode != NULL) {
		ComplexListNode *tmp = pNode->m_pNext;
		if (NULL != pNode->m_pSibling) {
			tmp->m_pSibling = pNode->m_pSibling->m_pNext; 
		}
		pNode = tmp->m_pNext;
	}
	
}

ComplexListNode *ReconnectNodes(ComplexListNode *pHead) {
	if (NULL == pHead) {
		return;
	}
	ComplexListNode *pNode = pHead;
	ComplexListNode *pClone = pNode->m_pNext;
	ComplexListNode *pCloneNode = pNode->m_pNext;

	pNode->m_pNext = pCloneNode->m_pNext;
	pNode = pNode->m_pNext;

	while (pNode != NULL) {
		pCloneNode->m_pNext = pNode->m_pNext;
		pCloneNode = pCloneNode->m_pNext;
		pNode->m_pNext = pCloneNode->m_pNext;
		pNode = pNode->m_pNext;
	}

	return pClone;
}

ComplexListNode *Clone(ComplexListNode *pHead) {
	// 赋值节点
	CloneNodes(pHead);
	// 连接sibling
	ConnectSiblingNodes(pHead);
	// 拆分复制链表
	ComplexListNode *dst = ReconnectNodes(pHead);
}