master-algorithms-py/linked_lists/detect_cycle_II.py
2023-08-07 15:56:27 -07:00

28 lines
413 B
Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# author: bt3gl
class Node:
def __init__(self, x):
self.val = x
self.next = None
def detect_cycle(head):
seen = set()
node = head
while node is not None:
if node in seen:
return node
else:
seen.add(node)
node = node.next
return None