【单链表面试题】--------链表的逆置

逆置单链表

/*三个指针*/
SListNode* ReverseList(SListNode* pHead)
{
SListNode* n1, *n2, *n3;
if (pHead == NULL || pHead->_next == NULL)
{
return pHead;
}
n1 = pHead;
n2 = n1->_next;
n3 = n2->_next;

n1->_next = NULL;
while (n2!=NULL)
{
n2->_next = n1;

n1 = n2;
n2 = n3;

if (n3 != NULL)
n3 = n3->_next;
}
return n1;

}

//头插
SListNode* ReverseList1(SListNode* pHead)
{
if (pHead == NULL || pHead->_next == NULL)
{
return pHead;
}

SListNode* NewList = NULL;
SListNode* cur = pHead;
while (cur)
{
SListPushFront(&NewList, cur->_data);
cur = cur->_next;
}
return NewList;
}