dsa-master/Data Structure/linked-list.js

A comprehensive data structures and algorithms library for JavaScript, featuring optimized implementations of common DS and algorithms.

class Node {
    constructor(value) {
        this.value = value;
        this.next = null;
    }
}

class LinkedList {
    constructor() {
        this.head = null;
        this.tail = null;
        this.size = 0;
    }

    // Insert at the end
    append(value) {
        let newNode = new Node(value);
        if (!this.head) {
            this.head = this.tail = newNode;
        } else {
            this.tail.next = newNode;
            this.tail = newNode;
        }
        this.size++;
    }

    // Insert at the beginning
    prepend(value) {
        let newNode = new Node(value);
        if (!this.head) {
            this.head = this.tail = newNode;
        } else {
            newNode.next = this.head;
            this.head = newNode;
        }
        this.size++;
    }

    // Delete a value
    delete(value) {
        if (!this.head) return false;
        if (this.head.value === value) {
            this.head = this.head.next;
            this.size--;
            return true;
        }
        let current = this.head;
        while (current.next && current.next.value !== value) {
            current = current.next;
        }
        if (current.next) {
            current.next = current.next.next;
            this.size--;
            return true;
        }
        return false;
    }

    display() {
        let current = this.head;
        let result = "";
        while (current) {
            result += current.value + " -> ";
            current = current.next;
        }
        console.log(result + "null");
    }
}

module.exports = LinkedList;

/**
 * Time Complexity:
 *  - append(): O(1)
 *  - prepend(): O(1)
 *  - delete(): O(n)
 * 
 * Space Complexity: O(n)
 */