Leetcode 206 Reverse Linked List 链表

将单向链表反转

完成如图操作，依次进行即可

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 /**
  * Definition for singly-linked list.
  * struct ListNode {
  *     int val;
  *     ListNode *next;
  *     ListNode(int x) : val(x), next(NULL) {}
  * };
  */
 class Solution {
 public:
     ListNode* reverseList(ListNode* head) {
         ListNode* now = head;
         head = NULL;
         while(now){
             ListNode* tnow= now;
             now = now->next;
             tnow->next = head;
             head = tnow;
         }
         return head;
     }
 };