[LeedCode]Remove Duplicates from Sorted List II
/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */ public class Solution { public ListNode deleteDuplicates(ListNode head) { ListNode pre = new ListNode(0); pre.next = head; head = pre; ListNode p = pre.next; while (p != null) { if (p.next != null && p.val == p.next.val) { ListNode q = p; while (q != null && q.val == p.val) { q = q.next; } pre.next = q; p = q; } else { pre = p; p = p.next; } } return head.next; } }