LeetCode #141: Linked List Cycle

LeetCode/easy/has_cycle_141.py

@@ -0,0 +1,21 @@
+from typing import Optional
+
+
+class ListNode:
+    def __init__(self, x):
+        self.val = x
+        self.next = None
+
+
+class Solution:
+    def hasCycle(self, head: Optional[ListNode]) -> bool:
+        slow, fast = head, head
+
+        while fast and fast.next:
+            slow = slow.next
+            fast = fast.next.next
+
+            if fast == slow:
+                return True
+
+        return False