Queue Data Structure

How Queue Works

A queue is a linear data structure that follows the First-In-First-Out (FIFO) principle. Elements are added to one end (rear) and removed from the other end (front) of the queue.

Key operations:

• Enqueue: Adds an element to the rear of the queue
• Dequeue: Removes and returns the element from the front of the queue
• Peek: Returns the front element without removing it

Time complexities:

• Enqueue: O(1)
• Dequeue: O(1)
• Peek: O(1)

Queues are used in many applications, including task scheduling in operating systems, breadth-first search in graph algorithms, and handling requests in web servers.

class Queue:
    items

    function enqueue(element):
        items.append(element)
        visualize()

    function dequeue():
        if isEmpty():
            return null
        element = items.removeFirst()
        visualize()
        return element

    function front():
        if isEmpty():
            return null
        return items[0]

    function isEmpty():
        return items.length == 0