参考文章：
- https://stackabuse.com/python-linked-lists/
- 04-单链表及结点的定义代码_哔哩哔哩_bilibili
- 代码随想录 (programmercarl.com)
- 题目参考：203. 移除链表元素
# Definition for singly-linked list.
# class ListNode:
# def __init__(self, val=0, next=None):
# self.val = val
# self.next = next
class Solution:
def removeElements(self, head: ListNode, val: int) -> ListNode:
#定义一个虚拟头节点并指向头节点
dummy_head=ListNode(next=head)
#定义一个cur指针进行遍历
cur=dummy_head
while(cur.next!=None):
if cur.next.val==val:
cur.next=cur.next.next#将指针指向下下一个节点
else:
cur=cur.next
return dummy_head.next
