LintCode-35.翻转链表

/**
 * Definition for ListNode.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int val) {
 *         this.val = val;
 *         this.next = null;
 *     }
 * }
 */ 
public class Solution {
    /**
     * @param head: The head of linked list.
     * @return: The new head of reversed linked list.
     */
    public ListNode reverse(ListNode head) {
        // write your code here
        //如果头指针为null或者只有头指针，直接返回
        if(head == null || head.next == null){
            return head;
        }

        ListNode reNode = reverse(head.next);
        head.next.next = head;
        head.next = null;
        return reNode;
    }
}