LeetCode 206. Reverse Linked Lis

Reverse a singly linked list.

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

题意：逆序一个链表

java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 prev = null;
        ListNode cur = head;
        while(cur!=null){
            ListNode next = cur.next; 
            cur.next = prev;
            prev = cur;
            cur = next;
        }
        return prev;
    }
}