给你单链表的头节点 head
,请你反转链表,并返回反转后的链表。
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode reverseList(ListNode head) {
ListNode pre = null;
ListNode temp = head;
ListNode next = head;
while(temp != null){
next = next.next;
temp.next = pre;
pre = temp;
temp = next;
}
return pre;
}
}