/* public class ListNode { int val; ListNode next = null; ListNode(int val) { this.val = val; } } */ public class Solution { public ListNode deleteDuplication(ListNode pHead) { if(pHead == null || pHead.next == null){ return pHead; } ListNode next = pHead.next; if (pHead.val == next.val) { while (next != null && pHead.val == next.val) next = next.next; return deleteDuplication(next); } else { pHead.next = deleteDuplication(pHead.next); return pHead; } } }