203.移除链表元素.py

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# @lc app=leetcode.cn id=203 lang=python3
#
# [203] 移除链表元素
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# https://leetcode-cn.com/problems/remove-linked-list-elements/description/
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# algorithms
# Easy (42.99%)
# Likes:    346
# Dislikes: 0
# Total Accepted:    60.6K
# Total Submissions: 137.1K
# Testcase Example:  '[1,2,6,3,4,5,6]\n6'
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# 删除链表中等于给定值 val 的所有节点。
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# 示例:
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# 输入: 1->2->6->3->4->5->6, val = 6
# 输出: 1->2->3->4->5
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#
#


# @lc code=start
# Definition for singly-linked list.
class ListNode:

    def __init__(self, x):
        self.val = x
        self.next = None


class Solution:

    def removeElements(self, head: ListNode, val: int) -> ListNode:
        dummy = ListNode(None)
        dummy.next = head

        prev = dummy
        curr = head
        while curr:
            if curr.val == val:
                prev.next = curr.next
            else:
                prev = curr
            curr = curr.next
        return dummy.next
      


# @lc code=end