Delete N Nodes After M Nodes of a Linked List

lcpy gen -n 1474   # by problem number
lcpy gen -s delete_n_nodes_after_m_nodes_of_a_linked_list   # by problem name

Input: head = [1,2,3,4,5,6,7,8,9,10,11,12,13], m = 2, n = 3
Output: [1,2,6,7,11,12]
Explanation: Keep the first (m = 2) nodes starting from the head of the linked List (1 -> 2) show in black nodes.
Delete the next (n = 3) nodes (3 -> 4 -> 5) show in red nodes.
Continue with the same procedure until reaching the tail of the Linked List.
Head of the linked list after removing nodes is returned.

Input: head = [1,2,3,4,5,6,7,8,9,10,11], m = 1, n = 3
Output: [1,5,9]
Explanation: Head of linked list after removing nodes is returned.

from leetcode_py import ListNode


class Solution:
    # Time: O(len(head))
    # Space: O(1)
    def delete_nodes(self, head: ListNode[int] | None, m: int, n: int) -> ListNode[int] | None:
        pre = head
        while pre:
            for _ in range(m - 1):
                if pre.next:
                    pre = pre.next
            cur = pre
            for _ in range(n):
                if cur.next:
                    cur = cur.next
            pre.next = cur.next
            pre = pre.next
        return head