diff --git a/linked_lists/detect_cycle_II.py b/linked_lists/detect_cycle_II.py new file mode 100644 index 0000000..c415bd2 --- /dev/null +++ b/linked_lists/detect_cycle_II.py @@ -0,0 +1,27 @@ +#!/usr/bin/env python3 +# -*- coding: utf-8 -*- +# author: bt3gl + + +class ListNode: + def __init__(self, x): + self.val = x + self.next = None + + +def detectCycle(self, 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 +