【剑指offer】反转链表

 1 /*
 2 struct ListNode {
 3     int val;
 4     struct ListNode *next;
 5     ListNode(int x) :
 6             val(x), next(NULL) {
 7     }
 8 };*/
 9 class Solution {
10 public:
11     ListNode* ReverseList(ListNode* pHead) {
12         ListNode* rev = NULL;//反转链表节点
13         ListNode* node = pHead;
14         ListNode* pre = NULL;
15         while(node != NULL){
16             ListNode *next = node->next;
17             if(next == NULL)    rev = node;
18             node->next = pre;
19             pre = node;
20             node = next;
21         }
22         return rev;
23     }
24 };