Question

Describe two operations that all queues perform.

Short answer

Answer: The two fundamental operations that all queues perform are "enqueue" and "dequeue." Enqueue adds an element to the rear of the queue, following the steps: (1) Check if the queue has enough capacity, (2) If there's space, add the element and move the rear pointer forward, (3) If the queue is full, display an error message. Dequeue removes an element from the front of the queue, following the steps: (1) Check if the queue is empty, (2) If not, remove the front element, move the front pointer forward, and return the dequeued element, (3) If empty, display an error message.

Step-by-step solution

Introduction to Queues

A queue is a linear data structure that follows the First In First Out (FIFO) ordering principle, meaning that the first element added to the queue will be the first one to be removed. Queues are used in various real-life applications, such as handling requests in a web server or scheduling tasks for execution in an operating system.

Operation 1: Enqueue

The first operation that all queues perform is called "enqueue," which is the process of adding an element to the end of the queue. Enqueuing an item adds it to the "rear" of the queue, as new elements always enter from the rear. This operation ensures that the order of the elements is maintained as per the FIFO principle. To enqueue an item, follow these steps: 1. Check if the queue is full or has enough capacity to accommodate the new element. 2. If there is enough space, add the new element to the rear of the queue and move the rear pointer forward. 3. If the queue is full, display an error message indicating that it's not possible to enqueue more items.

Operation 2: Dequeue

The second operation that all queues perform is called "dequeue," which is the process of removing an element from the front of the queue. Dequeuing an item removes it from the "front" of the queue since, according to the FIFO principle, the front element is the oldest and should be processed first. To dequeue an item, follow these steps: 1. Check if the queue is empty. 2. If the queue is not empty, remove the element from the front of the queue, move the front pointer forward, and return the dequeued element. 3. If the queue is empty, display an error message indicating that it's not possible to dequeue items from an empty queue.