删除链表中重复节点（递归）

public ListNode deleteDuplication(ListNode pHead){
    if(pHead == null || pHead.next == null)
        return pHead;
    ListNode current = pHead.next;
    
    // 如果是重复元素
    if(pHead.val == current.val){
        current = current.next;
        while(current != null && current.val == pHead.val)
            current = current.next;
        pHead = current;
        return deleteDuplication(current);
    }else{
        // pHead不是重复元素
        pHead.next = deleteDuplicaton(current);
        return pHead;
    }
}