leetcode 206

206. Reverse Linked List

Reverse a singly linked list.

翻转一个单链表。

代码如下：

 /**
  * 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* pre = NULL;
         ListNode* cur = head;
         while(cur != NULL)
         {
             ListNode* temp = cur->next;
             cur->next = pre;
             pre = cur;
             cur = temp;
         }
         return pre;
     }
 };