[LeetCode]83 删除排序链表中的重复元素

题目描述

给定一个排序链表，删除所有重复的元素，使得每个元素只出现一次。

示例1:

输入: 1->1->2
输出: 1->2

示例2:

输入: 1->1->2->3->3
输出: 1->2->3

代码

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# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution:
    def deleteDuplicates(self, head):
        """
        :type head: ListNode
        :rtype: ListNode
        """
        if not head:
            return None

        pre, cur = head, head.next
        while cur:
            if cur.val == pre.val:
                cur = cur.next
                pre.next = cur
            else:
                pre = pre.next
                cur = cur.next
        return head