翻转链表

题意

翻转一个链表

样例

给出一个链表 1->2->3->null,这个翻转后的链表为 3->2->1->null

代码实现

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/**
* 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) {
ListNode prev = null;
while (head != null) {
ListNode temp = head.next;
head.next = prev;
prev = head;
head = temp;
}
return prev;
}
}

图解

翻转链表.png-79.6kB

原题地址

LintCode:翻转链表