Skip to content

Latest commit

 

History

History
47 lines (39 loc) · 816 Bytes

0206 反转链表.md

File metadata and controls

47 lines (39 loc) · 816 Bytes

0206 反转链表

Question:

反转一个单链表。

示例:

输入: 1->2->3->4->5->NULL
输出: 5->4->3->2->1->NULL

进阶: 你可以迭代或递归地反转链表。你能否用两种方法解决这道题?

Solution:

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