shailendra9292 · July 16, 2018 04:12 · Jul 16, 2018
diff --git a/palindrome.py b/palindrome.py
@@ -0,0 +1,102 @@
+
+class node:
+    def __init__(self, data=None):
+        self.data = data
+        self.next = None
+
+
+class linked_list:
+
+    def __init__(self):
+        self.head = None
+
+    def insertBeg(self, data):
+        temp = node(data)
+        temp.next = self.head
+        self.head = temp
+
+    def compareList(self, headA , headB):
+        while headA and headB and (headA.data == headB.data):
+            headA = headA.next
+            headB = headB.next
+        return 1 if headA==headB else 0
+
+    def pallindrome(self,first_head,first_end,second_head,second_end):
+    	if self.length()== 1:
+    		print('Pallindrome')
+    		return
+    	first_end.next = None
+    	second_reverselist_head = self.reverse_list(second_head)
+    	res = self.compareList(first_head,second_reverselist_head)
+    	print("Pallindrome") if (res == 1) else print("Not Pallindrome")    # python conditonal statement(ternary)
+
+    def printList(self, head):
+	    p = head
+	    while p:
+	        print(p.data, end=' ')
+	        if p.next is not None:
+	            print('->', end=' ')
+	        p = p.next
+	    print()
+
+    def reverse_list(self, head):
+        if head is None or head.next is None :
+            return head
+        res = self.reverse_list(head.next)
+        head.next.next = head
+        head.next = None
+        return res
+
+    def middle_node(self):
+	    x = self.length() % 2  # check even-odd list
+	    p = self.head
+	    c = 1
+	    if self.length()==1:   
+	    	return self.head,self.head,self.head,self.head
+
+	    # end pointer for second list
+	    last = self.head
+	    while last.next:
+	        last = last.next
+
+	    while p:
+	        if x != 0:	 # odd list
+	            if (self.length() // 2) == c:
+	                # return first and last node of both the list
+	                return self.head, p, p.next.next, last	 # drop middle element(p.next) for odd list
+	            c += 1
+	            p = p.next
+
+	        elif x == 0:  # even list
+	            if self.length() // 2 == c:
+	                # return first and last node of both the list
+	                return self.head, p, p.next, last	
+	            c += 1
+	            p = p.next
+
+    def length(self):
+	    p = self.head
+	    c = 0
+	    while p:
+	        c += 1
+	        p = p.next
+	    return c
+
+
+
+l = linked_list()
+l.insertBeg(9)
+l.insertBeg(4)
+l.insertBeg(5)
+l.insertBeg(2)
+l.insertBeg(7)
+l.insertBeg(2)
+l.insertBeg(5)
+l.insertBeg(4)
+l.insertBeg(9)
+print("\nnode length is {} ".format(l.length()))
+print('list is....')
+l.printList(l.head)
+first_head,first_end, second_head,second_end= l.middle_node()
+l.pallindrome(first_head,first_end, second_head,second_end)
+print()
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