LeetCode083 Remove Duplicates from Sorted List

最新推荐文章于 2022-04-06 16:22:53 发布

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本文介绍了一种算法，用于从已排序的链表中移除重复元素，确保每个元素只出现一次。通过两个示例说明了该算法的工作原理及实现过程。

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

Example 1:

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

Example 2:

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

<思路>如果链表为空，或者只有一个节点，直接返回。如果链表有下一个节点，比较val，相同则将next越过，不同则继续向下查找。

# 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
        """
        if not head:
            return head
        
        rhead = head
        while head.next:
            if head.val==head.next.val:
                head.next = head.next.next
            else:  
                head = head.next
        return rhead

新建一个链表，把符合要求的点加进去

# 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 = p = ListNode(-1)
        p.next = head
        while head and head.next:
            while head.next and head.val==head.next.val:
                head=head.next
            head=head.next
            p=p.next
            p.next=head

        return dummy.next