// java 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; } }