面试题13：在O(1)时间删除链表节点

void DeleteNode(ListNode** pListHead, ListNode* pToBeDeleted)
{
if(!pListHead || !pToBeDeleted)
return;

// 要删除的结点不是尾结点
if(pToBeDeleted->m_pNext != NULL)
{
ListNode* pNext = pToBeDeleted->m_pNext;
pToBeDeleted->m_nValue = pNext->m_nValue;
pToBeDeleted->m_pNext = pNext->m_pNext;

delete pNext;
pNext = NULL;
}
// 链表只有一个结点，删除头结点（也是尾结点）
else if(*pListHead == pToBeDeleted)
{
delete pToBeDeleted;
pToBeDeleted = NULL;
*pListHead = NULL;
}
// 链表中有多个结点，删除尾结点
else
{
ListNode* pNode = *pListHead;
while(pNode->m_pNext != pToBeDeleted)
{
pNode = pNode->m_pNext;
}

pNode->m_pNext = NULL;
delete pToBeDeleted;
pToBeDeleted = NULL;
}
}