When it is required to remove the duplicate elements in a doubly linked list, a ‘Node’ class needs to be created. In this class, there are three attributes, the data that is present in the node, the access to the next node of the linked list, and the access to the previous node of the linked list.
Below is a demonstration for the same −
class Node: def __init__(self, my_data): self.previous = None self.data = my_data self.next = None class double_list: def __init__(self): self.head = None self.tail = None def add_data(self, my_data): new_node = Node(my_data) if(self.head == None): self.head = self.tail = new_node self.head.previous = None self.tail.next = None else: self.tail.next = new_node new_node.previous = self.tail self.tail = new_node self.tail.next = None def print_it(self): curr = self.head if (self.head == None): print("The list is empty") return print("The nodes in the doubly linked list are :") while curr != None: print(curr.data) curr = curr.next def remove_duplicates(self): if(self.head == None): return else: curr = self.head; while(curr != None): index_val = curr.next while(index_val != None): if(curr.data == index_val.data): temp = index_val index_val.previous.next = index_val.next if(index_val.next != None): index_val.next.previous = index_val.previous temp = None index_val = index_val.next curr = curr.next my_instance = double_list() print("Elements are being added to the doubly linked list") my_instance.add_data(10) my_instance.add_data(24) my_instance.add_data(54) my_instance.add_data(77) my_instance.add_data(24) my_instance.print_it() print("The elements in the list after removing duplicates are : ") my_instance.remove_duplicates() my_instance.print_it()
Elements are being added to the doubly linked list The nodes in the doubly linked list are : 10 24 54 77 24 The elements in the list after removing duplicates are : The nodes in the doubly linked list are : 10 24 54 77