https://leetcode.com/problems/linked-list-cycle

easy/linked_list_cycle.py

@@ -0,0 +1,23 @@
+# https://leetcode.com/problems/linked-list-cycle
+
+from typing import Optional
+
+class ListNode:
+    val: int
+    next: Optional["ListNode"]
+
+class Solution:
+    def hasCycle(self, head: Optional[ListNode]) -> bool:
+        first: Optional[ListNode] = head
+        second: Optional[ListNode] = head
+
+        while first is not None and \
+            first.next is not None and \
+            second is not None:
+
+            first = first.next.next
+            second = second.next
+            if first == second:
+                return True
+        return False
+