328. Odd Even Linked List

https://leetcode.com/problems/odd-even-linked-list

Python

class Solution:
    def oddEvenList(self, head: Optional[ListNode]) -> Optional[ListNode]:
        is_odd = True

        odd_head = ListNode(None, None)
        odd_node = odd_head
        even_head = ListNode(None, None)
        even_node = even_head

        current = head

        while current:
            if is_odd:
                odd_node.next = current
                odd_node = current
            else:
                even_node.next = current
                even_node = current

            current = current.next
            is_odd = not is_odd

        even_node.next = None
        odd_node.next = even_head.next

        return odd_head.next