/*
struct ListNode {
int val;
struct ListNode *next;
ListNode(int x) :
val(x), next(NULL) {
}
};*/
class Solution {
public:
ListNode* ReverseList(ListNode* pHead) {
if(pHead == nullptr) return pHead;
ListNode *pre,*cur,*next;
pre = nullptr;
cur = pHead;
next = pHead->next;
while(next)
{
cur->next = pre;
pre = cur;
cur = next;
next = next->next;
}
cur->next = pre;
return cur;
}
};