Remove Linked List Elements.py

#!/usr/bin/python

'''
Given the head of a linked list and an integer val, remove all the nodes of the linked list that has Node.val == val, and return the new head.
'''

# 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]:
        while head and head.val == val:
            head = head.next
        dummy = head
        while dummy:
            while dummy.next and (dummy.next.val == val):
                dummy.next = dummy.next.next
            dummy = dummy.next
        return head