Reverse Linked List

public class Solution {
    public ListNode reverseList(ListNode head) {
        if(head==null || head.next==null)   return head;
        ListNode dummy = new ListNode(-1);
        dummy.next = head;
        ListNode cur = head.next;
        while(cur != null)
        {
            ListNode next = cur.next;
            cur.next = dummy.next;
            dummy.next = cur;
            cur = next;
        }
        head.next = null;
        return dummy.next;
    }
}