Merge pull request #452 from kiss-me1997/master

Detect loop in a linked list

Author: probot-auto-merge[bot]

finding cycle in linked list/cycle.py

@@ -0,0 +1,48 @@
+class Node: 
+  
+    # Constructor to initialize the node object 
+    def __init__(self, data): 
+        self.data = data 
+        self.next = None
+  
+class LinkedList: 
+  
+    # Function to initialize head 
+    def __init__(self): 
+        self.head = None
+  
+    # Function to insert a new node at the beginning 
+    def push(self, new_data): 
+        new_node = Node(new_data) 
+        new_node.next = self.head 
+        self.head = new_node 
+  
+    # Utility function to prit the linked LinkedList 
+    def printList(self): 
+        temp = self.head 
+        while(temp): 
+            print (temp.data), 
+            temp = temp.next
+  
+  
+    def detectLoop(self): 
+        slow_p = self.head 
+        fast_p = self.head 
+        while(slow_p and fast_p and fast_p.next): 
+            slow_p = slow_p.next
+            fast_p = fast_p.next.next
+            if slow_p == fast_p: 
+                print ("Found Loop")
+                return
+        print ("Not Found Loop")
+  
+# Driver program for testing 
+llist = LinkedList() 
+llist.push(20) 
+llist.push(4) 
+llist.push(15) 
+llist.push(10) 
+  
+# Create a loop for testing 
+llist.head.next.next.next.next = llist.head 
+llist.detectLoop()