Queue Basics

Overview

A queue is a data structure that stores items in a specific order, following the First In, First Out principle. This means the first item added is always the first item removed, similar to people waiting in line at a store.

FIFO Principle

FIFO stands for First In, First Out. Items enter the queue at one end, called the rear or back, and leave from the other end, called the front. The order items are added is exactly the order they are removed, ensuring fairness.

Core Operations

Queues have two main operations. Enqueue adds an item to the rear of the queue. Dequeue removes and returns the item at the front. These operations maintain the FIFO order and are essential for queue behavior.

Real-World Analogy

A queue works like a line of people waiting. New people join at the back, and the person at the front is served first. This ensures everyone gets their turn in the order they arrived, making queues perfect for scheduling tasks fairly.

When Queues Are Useful

Queues are ideal when you need to process items in the exact order they arrive. Common uses include task scheduling, printing jobs, handling requests on a server, and implementing breadth-first search in graphs.