Data Science School

• What is a Linked List?
  • A linked list is a data structure used to store a collection of elements.
  • It consists of individual elements, called nodes, which are linked together in a linear sequence.
• Node in a Linked List:
  • Each node in a linked list contains two parts:
    1. Data: The actual value or information you want to store.
    2. Pointer (or Reference): A reference to the next node in the sequence.
• Types of Linked Lists:
  • There are different types of linked lists, including:
    • Singly Linked List: Each node points to the next node.
    • Doubly Linked List: Each node points to both the next and the previous node.
    • Circular Linked List: The last node points back to the first node, forming a closed loop.
• Advantages of Linked Lists:
  • Linked lists are dynamic data structures, which means they can grow or shrink as needed.
  • They allow for efficient insertions and deletions at any position in the list.
• Drawbacks of Linked Lists:
  • Accessing elements in a linked list may be slower than arrays since you have to traverse the list from the beginning.
  • Linked lists use more memory than arrays because of the additional pointers.
• Example:
  • Consider a singly linked list containing values: 10 -> 20 -> 30.
  • In this list, the node with a value of 10 points to the node with a value of 20, and the node with a value of 20 points to the node with a value of 30. The last node points to null to indicate the end of the list.
• Operations on Linked Lists:
  • Common operations include adding a node to the beginning or end, deleting a node, searching for a node with a specific value, and traversing the list to perform actions on each node.
• Use Cases:
  • Linked lists are often used in situations where you need dynamic and efficient data storage, like in implementing data structures such as stacks, queues, and hash tables.

In summary, a linked list is a flexible data structure consisting of nodes connected in a sequence, making it useful for various applications where elements need to be stored and manipulated efficiently.

The following linked list example is written using Dart Programming language

import 'dart:collection';
base class Data<T> extends LinkedListEntry<Data<T>> {
  T value;
  Data(this.value);

  @override
  String toString() {
    return '$value';
  }
}

void main() {
  // Create a list
  var linkedList = LinkedList<Data<int>>();

  // Add elements to the end of the list
  linkedList.add(Data(20));
  linkedList.add(Data(30));
  linkedList.addFirst(Data(10)); // to add data in first position

  // Print the entire linked list
  print("linkedList is: $linkedList");

  // Access a specific node (e.g., the second node at index 1)
  var currentNode = linkedList.elementAt(0);
  print("Current Node Value: ${currentNode.value}");

  // Access the value of the next node
  var nextNode = currentNode.next;
  if (nextNode != null) {
    print("Next Node Value: ${nextNode.value}");
  } else {
    print("No next node available.");
  }
}