Create Sublist_search_python

Python/Sublist_search_python

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+# Python3 program to find a list in second list
+class Node:
+	def __init__(self, value = 0):
+
+		self.value = value
+		self.next = None
+
+# Returns true if first list is
+# present in second list
+def findList(first, second):
+
+	# If both linked lists are empty/None,
+	# return True
+	if not first and not second:
+		return True
+
+	# If ONLY one of them is empty,
+	# return False
+	if not first or not second:
+		return False
+
+	ptr1 = first
+	ptr2 = second
+
+	# Traverse the second LL by
+	# picking nodes one by one
+	while ptr2:
+
+		# Initialize 'ptr2' with current
+		# node of 'second'
+		ptr2 = second
+
+		# Start matching first LL
+		# with second LL
+		while ptr1:
+
+			# If second LL become empty and
+			# first not, return False,
+			# since first LL has not been
+			# traversed completely
+			if not ptr2:
+				return False
+
+			# If value of both nodes from both
+			# LLs are equal, increment pointers
+			# for both LLs so that next value
+			# can be matched
+			elif ptr1.value == ptr2.value:
+				ptr1 = ptr1.next
+				ptr2 = ptr2.next
+
+			# If a single mismatch is found
+			# OR ptr1 is None/empty,break out
+			# of the while loop and do some checks
+			else:
+				break
+
+		# check 1 :
+		# If 'ptr1' is None/empty,that means
+		# the 'first LL' has been completely
+		# traversed and matched so return True
+		if not ptr1:
+			return True
+
+		# If check 1 fails, that means, some
+		# items for 'first' LL are still yet
+		# to be matched, so start again by
+		# bringing back the 'ptr1' to point
+		# to 1st node of 'first' LL
+		ptr1 = first
+
+		# And increment second node element to next
+		second = second.next
+
+	return False
+
+# Driver Code
+
+# Let us create two linked lists to
+# test the above functions.
+# Created lists would be be
+# node_a: 1->2->3->4
+# node_b: 1->2->1->2->3->4
+node_a = Node(1)
+node_a.next = Node(2)
+node_a.next.next = Node(3)
+node_a.next.next.next = Node(4)
+
+node_b = Node(1)
+node_b.next = Node(2)
+node_b.next.next = Node(1)
+node_b.next.next.next = Node(2)
+node_b.next.next.next.next = Node(3)
+node_b.next.next.next.next.next = Node(4)
+
+if findList(node_a, node_b):
+	print("LIST FOUND")
+else:
+	print("LIST NOT FOUND")
+