kanthuc
diff --git a/‎data_structures/linked_list/has_loop.py
Lines changed: 51 additions & 0 deletions b/‎data_structures/linked_list/has_loop.py
Lines changed: 51 additions & 0 deletions
@@ -0,0 +1,51 @@
+from typing import Any
+
+
+class Node:
+    def __init__(self, data: Any) -> None:
+        self.data = data
+        self.next_node = None
+ 
+    def __iter__(self):
+        node = self
+        while node:
+            yield node.data
+            node = node.next_node
+     
+    def has_loop(self) -> bool:
+        >>> node1 = Node(1)
+        >>> node1.next_node = Node(2)
+        >>> node1.next_node.next_node = Node(3)
+        >>> node1.next_node.next_node.next_node = Node(4)
+        >>> node1.next_node.next_node.next_node = node1.next_node
+        >>> has_loop(node1)
+        True
+
+        >>> node2 = Node(1)
+        >>> node2.next_node = Node(2)
+        >>> node2.next_node.next_node = Node(1)
+        >>> node2.next_node.next_node.next_node = Node(2)
+        >>> contains_loop(node2)
+        False
+        """
+        return len(list(self)) != len(set(self))
+
+
+if __name__ == "__main__":
+    node1 = Node(1)
+    node1.next_node = Node(2)
+    node1.next_node.next_node = Node(3)
+    node1.next_node.next_node.next_node = Node(4)
+    node1.next_node.next_node.next_node = node1.next_node
+    print(has_loop(node1))
+
+    node2 = Node(5)
+    node2.next_node = Node(6)
+    node2.next_node.next_node = Node(5)
+    node2.next_node.next_node.next_node = Node(6)
+    print(has_loop(node2))
+
+    node3 = Node(1)
+    # node3.next_node = Node(2)
+    # node3.next_node.next_node = node3
+    print(has_loop(node3))