Python Program to Find the Length of the Linked List without using Recursion

When it is required to find the length of a linked list without using recursion, a method to add elements to the linked list, and a method to calculate the length of the linked list is defined.

Below is a demonstration for the same −

Example

 Live Demo

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

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

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

   def calculate_length(self):
      curr = self.head
      length_val = 0
      while curr:
         length_val = length_val + 1
         curr = curr.next
      return length_val

my_instance = my_linked_list()
my_data = input('Enter elements of the linked list ').split()
for elem in my_data:
   my_instance.add_value(int(elem))
print('The length of the linked list is ' + str(my_instance.calculate_length()))

Output

Enter elements of the linked list 34 12 56 86 32 99 0 6
The length of the linked list is 8

Explanation

• The ‘Node’ class is created.

• Another ‘my_linked_list’ 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’.

• Another method named ‘add_value’ is defined, that is used to add data to the linked list.

• Another method named ‘calculate_length’ is defined that is used to find the length of the linked list.

• An object of the ‘my_linked_list’ class is created.

• The user input is taken to get the elements in the linked list.

• The methods are called on it to add data.

• The calculate_length method is called, to find the length of the list.

• This output is displayed on the console.