203. Remove Linked List Elements - LeetCode Solution

# 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: Optional[ListNode], val: int) -> Optional[ListNode]:
        if not head:
            return None
        
        a = ListNode(0)
        ans = a
        
        while head:
            if head.val != val:
                ans.next = ListNode(head.val)
                ans = ans.next
            
            head = head.next
        
        return a.next