203. Remove Linked List Elements

Remove all elements from a linked list of integers that have value val.

Example:

Input: 1->2->6->3->4->5->6, val = 6 Output: 1->2->3->4->5 Accepted

思路：两个节点，一个的next指向head，一个遍历，如果下个节点的val与val相等就pointer.next=pointer.next.next 指针指向下下个节点

代码：python3

class Solution:
    def removeElements(self, head: ListNode, val: int) -> ListNode:
        node = ListNode(-1)
        node.next = head
        pointer = node
        while pointer.next:
            if pointer.next.val == val:
                pointer.next = pointer.next.next
            else:
                pointer = pointer.next
        return node.next