题目描述

在一个排序的链表中，存在重复的结点，请删除该链表中重复的结点，重复的结点不保留，返回链表头指针。 例如，链表1->2->3->3->4->4->5 处理后为 1->2->5
说明：本题目包含复杂数据结构ListNode，点此查看相关信息

  1. # -*- coding:utf-8 -*-
  2. # class ListNode:
  3. #     def __init__(self, x):
  4. #         self.val = x
  5. #         self.next = None
  6. class Solution:
  7.     def deleteDuplication(self, pHead):
  8.         # write code here
  9.         if not pHead or not pHead.next:
  10.             return pHead
  11.         Head = ListNode(-1)
  12.         Head.next = pHead
  13.         p_back = Head
  14.         p_front = Head.next
  15.         while p_front:
  16.             if p_front.next and p_front.val==p_front.next.val:
  17.                 while p_front.next and p_front.val==p_front.next.val:
  18.                     p_front = p_front.next
  19.                 p_front = p_front.next
  20.                 p_back.next = p_front
  21.             else:
  22.                 p_back = p_front
  23.                 p_front = p_front.next
  24.         return Head.next