Middle of the Linked List Python Solution

lcpy gen -n 876   # by problem number
lcpy gen -s middle_of_the_linked_list   # by problem name

Input: head = [1,2,3,4,5]
Output: [3,4,5]

Input: head = [1,2,3,4,5,6]
Output: [4,5,6]

from leetcode_py import ListNode


class Solution:
    # Time: O(n)
    # Space: O(1)
    def middle_node(self, head: ListNode[int] | None) -> ListNode[int] | None:
        slow = fast = head
        while fast and fast.next:
            assert slow is not None
            slow = slow.next
            fast = fast.next.next
        return slow