Python Program to Check whether 2 Linked Lists are Same

PythonServer Side ProgrammingProgramming

When it is required to check if two linked lists are same, a method to add elements to the linked list, and a method to check the equality of the elements in the linked lists are defined.

Below is a demonstration for the same −

Example

class Node:
   def __init__(self, data):
      self.data = data
      self.next = None

class LinkedList_structure:
   def __init__(self):
      self.head = None
      self.last_node = None

   def add_vals(self, data):
      if self.last_node is None:
         self.head = Node(data)
         self.last_node = self.head
      else:
         self.last_node.next = Node(data)
         self.last_node = self.last_node.next

def check_equality(list_1, list_2):
   curr_1 = list_1.head
   curr_2 = list_2.head
   while (curr_1 and curr_2):
      if curr_1.data != curr_2.data:
         return False
      curr_1 = curr_1.next
      curr_2 = curr_2.next
   if curr_1 is None and curr_2 is None:
      return True
   else:
      return False

my_linked_list_1 = LinkedList_structure()
my_linked_list_2 = LinkedList_structure()

my_list = input('Enter the elements of the first linked list: ').split()
for elem in my_list:
   my_linked_list_1.add_vals(int(elem))

my_list = input('Enter the elements of the second linked list: ').split()
for elem in my_list:
   my_linked_list_2.add_vals(int(elem))

if check_equality(my_linked_list_1, my_linked_list_2):
   print('The two linked lists are the same')
else:
   print('The two linked list are not same')

Output

Enter the elements of the first linked list: 34 56 89 12 45
Enter the elements of the second linked list: 57 23 78 0 2
The two linked list are not same

Explanation

  • The ‘Node’ class is created.

  • Another ‘LinkedList_structure’ class with required attributes is created.

  • It has an ‘init’ function that is used to initialize the first element, i.e the ‘head’ to ‘None’ and ‘last_node’ to ‘None’.

  • A method named ‘add_vals’ is defined, that helps add a value to the stack.

  • Another method named ‘check_equality’ is defined, that helps check if elements in two linked list are same or not.

  • It returns True or False depending on the equality.

  • Two instances of the ‘LinkedList_structure’ are created.

  • Elements are added to the two linked lists.

  • The ‘check_equality’ method is called on these two linked lists.

  • The output is displayed on the console.

raja
Published on 14-Apr-2021 13:35:26
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