Remove duplicates from an unsorted linked list Python

PROGRAM TO REMOVE DUPLICATES FROM A SORTED LINKED LIST

class Node:

     

    def __init__(self, data):

         

        self.data = data

        self.next = None

 

class LinkedList:

     

    def __init__(self):

         

        self.head = None

         

    # Function to print nodes in a 

    # given linked list

    def printlist(self):

         

        temp = self.head

         

        while (temp):

            print(temp.data, end = " ")

            temp = temp.next

             

    # Function to remove duplicates from a

    # unsorted linked list

    def removeDuplicates(self, head):

         

        # Base case of empty list or

        # list with only one element

        if self.head is None or self.head.next is None:

            return head

             

        # Hash to store seen values

        hash = set() 

 

        current = head

        hash.add(self.head.data)

 

        while current.next is not None:

 

            if current.next.data in hash:

                current.next = current.next.next

            else:

                hash.add(current.next.data)

                current = current.next

 

        return head

 

# Driver code

if __name__ == "__main__":

     

    # Creating Empty list

    llist = LinkedList()

    llist.head = Node(10)

    second = Node(12)

    third = Node(11)

    fourth = Node(11)

    fifth = Node(12)

    sixth = Node(11)

    seventh = Node(10)

     

    # Connecting second and third

    llist.head.next = second

    second.next = third

    third.next = fourth

    fourth.next = fifth

    fifth.next = sixth

    sixth.next = seventh

 

    # Printing data

    print("Linked List before removing Duplicates.")

    llist.printlist()

    llist.removeDuplicates(llist.head)

    print("\nLinked List after removing duplicates.")

    llist.printlist()




OUTPUT

Linked list before removing duplicates:
 10 12 11 11 12 11 10 
Linked list after removing duplicates:
 10 12 11

CREDITS: https://www.geeksforgeeks.org/remove-duplicates-from-an-unsorted-linked-list/