83. Remove Duplicates from Sorted List

2019-06-07

83. Remove Duplicates from Sorted List

Given a sorted linked list, delete all duplicates such that each element appear only once.

Example 1:

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Input: 1->1->2
Output: 1->2

Example 2:

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Input: 1->1->2->3->3
Output: 1->2->3

Code：

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

class Solution(object):
    def deleteDuplicates(self, head):
        """
        :type head: ListNode
        :rtype: ListNode
        """
        dummy = pre = ListNode(0)
        dummy.next = head
        while head and head.next:
            if head.val == head.next.val:
                while head and head.next and head.val == head.next.val:
                    head = head.next
                pre.next = head
            else:
                pre = pre.next
                head = head.next
        return dummy.next
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