linked-list

A TypeScript implementation of a generic singly-linked list.

Contents

• Installation
• Usage
  • Creating a LinkedList
  • Appending Elements
  • Prepending Elements
  • Deleting Elements
  • Looking Up By Position
  • Finding the Position of a Value
  • Inserting Elements at a Specific Position
  • Converting to Array
• Using the reverseLinkedList Helper
• API
  • Core Methods
  • Auxiliary Methods
• Helper Methods

Installation

To install this package, run:

Installation

To install this package, run:

npm install @sandro-e-martinez/linked-list

Usage

First, import the LinkedList class:

import { LinkedList } from '@sandro-e-martinez/linked-list';

Creating a LinkedList

Create a new linked list:

const list = new LinkedList<number>();

Appending Elements

Append elements to the end of the list:

list.append(1);
list.append(2);
list.append(3);

Prepending Elements

Prepend elements to the beginning of the list:

list.prepend(0);

Deleting Elements

Delete the first node with a given value:

list.delete(2);

Looking Up By Position

Retrieve a node based on its position (1-based index):

let nodeAtThirdPosition = list.lookup(3);

Finding the Position of a Value

Find the position (1-based index) of the first occurrence of a value:

let positionOfValue2 = list.indexOf(2); // should return 2 if the list has the value 2 at the second position

Inserting Elements at a Specific Position

Insert a value at a specific position (1-based index):

list.insert(2, 1.5); // inserts the value 1.5 at the second position

Converting to Array

Convert the list to an array:

const arr = list.toArray();

Using the reverseLinkedList Helper

For more advanced reversing tasks, like reversing only a specific part of the list, you can use the reverseLinkedList helper function. First, import the helper:

import { reverseLinkedList } from '@sandro-e-martinez/linked-list/helpers/reverse';

const list = new LinkedList<number>();
list.append(1);
list.append(2);
list.append(3);
list.append(4);
list.append(5);

// Original list: [1, 2, 3, 4, 5]
list = new LinkedList(reverseLinkedList(list.head)); // Reverse entire list
// Output list [5, 4, 3, 2, 1]

// To reverse a sublist from the 2nd to 4th node (1-based index)
list = reverseLinkedList(list.head, 2, 4);
// Output list [1, 4, 3, 2, 5]

API

Core Methods

These are the fundamental methods for manipulating the singly-linked list, including appending, prepending, and deleting nodes.

append(value: T): void

Appends a new node with the given value to the end of the list.

prepend(value: T): void

Prepends a new node with the given value to the beginning of the list.

delete(value: T): void

Deletes the first node with the given value from the list.

lookup(position: number): Node<T> | null

Retrieves a node from the linked list based on its position.

indexOf(value: T): number

Returns the position of the first node with the given value.

insert(position: number, value: T): void

Inserts a value at a specific position.

Auxiliary Methods

toArray(): T[]

Returns an array containing all the elements of the linked list.

Helper Methods

These methods provide additional capabilities for manipulating your linked list, such as reversing it entirely or partially.

reverse(from?: number, to?: number): void

Reverses the entire list if no parameters are provided. Reverses a sublist from position from to position to if both are provided.