[leetcode]206. Reverse Linked List反转链表

Reverse a singly linked list.

Input: 1->2->3->4->5->NULL
Output: 5->4->3->2->1->NULL

Follow up:

A linked list can be reversed either iteratively or recursively. Could you implement both?

题意：

如题

思路：

无

代码：

 /**
  * Definition for singly-linked list.
  * public class ListNode {
  *     int val;
  *     ListNode next;
  *     ListNode(int x) { val = x; }
  * }
  */
 class Solution {
     public ListNode reverseList(ListNode head) {
             ListNode cur = head;
             ListNode pre = null;
         while(cur!= null){
             ListNode temp = cur.next;
             cur.next = pre;
             cur = temp;
         }
     }
 }