题目
输入一个链表，反转链表后，输出新链表的表头。
/*
struct ListNode {
int val;
struct ListNode *next;
ListNode(int x) :
val(x), next(NULL) {
}
};*/
class Solution {
public:
ListNode* ReverseList(ListNode* pHead) {
ListNode * pReverseHead = nullptr;
ListNode * pNode = pHead;
ListNode * pPre = nullptr;
while(pNode != nullptr)
{
ListNode * pNext = pNode->next;
if(pNext == nullptr)
{
pReverseHead = pNode;
}
pNode->next = pPre;
pPre = pNode;
pNode = pNext;
}
return pReverseHead;
}
};
