Python Program to Remove Duplicates from a Linked List

# Introduction
# In this Python program, we will create a singly linked list and remove duplicate elements from it. A linked list is a data structure consisting of nodes, where each node contains a value and a reference (or link) to the next node in the list.

# Problem Statement
# Given a linked list, remove any duplicate elements so that only the distinct elements remain in the list.

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

class LinkedList:
    def __init__(self):
        self.head = None

    def append(self, data):
        new_node = Node(data)
        if self.head is None:
            self.head = new_node
            return
        current = self.head
        while current.next:
            current = current.next
        current.next = new_node

    def display(self):
        current = self.head
        while current:
            print(current.data, end=' ')
            current = current.next
        print()

    def remove_duplicates(self):
        current = self.head
        while current:
            runner = current
            while runner.next:
                if runner.next.data == current.data:
                    runner.next = runner.next.next
                else:
                    runner = runner.next
            current = current.next

# How it Works
# 1. We define two classes, Node and LinkedList. Node represents an element in the linked list, and LinkedList is used to manage the list.
# 2. The `append` method is used to add elements to the linked list.
# 3. The `display` method is used to print the elements of the linked list.
# 4. The `remove_duplicates` method is used to remove duplicate elements from the linked list.
# 5. We iterate through the list, and for each element, we iterate through the rest of the list to remove any duplicates.

# Input/Output
if __name__ == "__main__":
    linked_list = LinkedList()
    elements = [1, 2, 2, 3, 4, 4, 5]

    for element in elements:
        linked_list.append(element)

    print("Original Linked List:")
    linked_list.display()

    linked_list.remove_duplicates()
    print("\nLinked List after removing duplicates:")
    linked_list.display()