删除链表中的重复的结点_56

  public ListNode deleteDuplication(ListNode pHead) {
        if (pHead == null ) {
            return pHead;
        }
        //辅助头结点(真正头结点前面一个结点)用于避免第一个数字就重读的情况
        ListNode tempHeadPre = new ListNode(0);

        //当前已遍历的最后一个不重复的结点
        ListNode preNoDup = tempHeadPre;

        preNoDup.next = pHead;

        //当前结点的前面一个结点
        ListNode pre = pHead;
        //当前结点
        ListNode curr = pre.next;


        while (curr != null) {
            if (curr.val == pre.val) {
                while (curr!= null && curr.val == pre.val) {
                    curr = curr.next;
                }
                preNoDup.next = curr;
                if (curr == null) {
                    return tempHeadPre.next;
                } else {
                    pre = preNoDup.next;
                    curr = pre.next;
                }
            } else {
                preNoDup = pre;
                pre = curr;
                curr = curr.next;
            }
        }
        return tempHeadPre.next;
    }