From 0127f053c26aaeeb203cc3c7aefd5f564fc8a61d Mon Sep 17 00:00:00 2001
From: Eshika Gupta <eshikagupta001@gmail.com>
Date: Sat, 5 Oct 2024 18:38:36 +0530
Subject: [PATCH] Created linkedlist_hasCycle.py

---
 .../linkedlist_hasCycle.py                    | 55 +++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 DS&Algo Programs in Python/linkedlist_hasCycle.py

diff --git a/DS&Algo Programs in Python/linkedlist_hasCycle.py b/DS&Algo Programs in Python/linkedlist_hasCycle.py
new file mode 100644
index 00000000..6a09206b
--- /dev/null
+++ b/DS&Algo Programs in Python/linkedlist_hasCycle.py	
@@ -0,0 +1,55 @@
+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:
+
+        #if no linkedlist or a single node linkedlist
+        if head is None or head.next is None:
+            return False
+        
+        slow=head
+        fast=head
+    
+        while slow!=fast:
+            if fast is None or fast.next is None:
+                return False
+            
+            slow=slow.next #goes to next node
+            fast=fast.next.next #goes to next to next node
+        
+        return True
+    
+# Create some nodes for a linked list
+node1 = ListNode(1)
+node2 = ListNode(2)
+node3 = ListNode(3)
+node4 = ListNode(4)
+node5 = ListNode(5)
+node6 = ListNode(6)
+node7 = ListNode(7)
+
+# Link the nodes together
+node1.next = node2
+node2.next = node3
+node3.next = node4
+node4.next = node5
+node5.next = node6
+node6.next = node7
+
+# Optionally create a cycle
+# Uncomment the line below to create a cycle
+node6.next = node3
+
+# Create an instance of the Solution class
+solution = Solution()
+
+# Check if the linked list has a cycle
+result = solution.hasCycle(node1)
+
+# Print the result
+print("Cycle detected!" if result else "No cycle detected")