# Which Algorithm Uses Queue Data Structure?

//

Angela Bailey

When it comes to data structures and algorithms, queues play a crucial role in many applications. A queue is a linear data structure that follows the First-In-First-Out (FIFO) principle, meaning that the element that is inserted first will be the first one to be removed. In this article, we will explore which algorithms utilize the queue data structure and how they benefit from its properties.

## The Queue Data Structure

Before diving into specific algorithms, let’s quickly recap what a queue is. A queue has two primary operations:

• Enqueue: This operation adds an element to the end of the queue.
• Dequeue: This operation removes an element from the front of the queue.

The simplicity of these operations makes queues ideal for scenarios where elements need to be processed in a specific order. Now, let’s move on to some algorithms that effectively utilize queues!

BFS is a graph traversal algorithm that explores all vertices of a graph in breadth-first order. It uses a queue to keep track of vertices that are yet to be explored.

To implement BFS using a queue, we start by enqueueing the initial vertex. Then, while there are still vertices in the queue, we dequeue one vertex at a time and enqueue its adjacent vertices. This ensures that we visit all vertices at each level before moving deeper into the graph.

## Scheduling Algorithms

Scheduling algorithms often rely on queues to manage tasks or processes. One such algorithm is Round Robin Scheduling, commonly used in operating systems.

In Round Robin Scheduling, processes are assigned fixed time slices called quantum. The processes are enqueued in a circular queue, and each process gets a turn to execute for its allocated quantum. Once the quantum expires, the process is dequeued and placed back at the end of the queue, allowing other processes to get their chance.

## Printer Spooler

A printer spooler is an application that manages multiple print jobs in a shared printing environment. It uses a queue to maintain the order of print requests.

When a user sends a print request, it is enqueued in the printer spooler. The printer then dequeues each print job one by one and processes them in the order they were received. This ensures fairness and prevents any single user from monopolizing the printer.

## Conclusion

The queue data structure finds applications in various algorithms where maintaining order or processing elements in a specific sequence is crucial. Whether it’s graph traversal algorithms like BFS, scheduling algorithms, or managing print jobs with a printer spooler, queues provide an elegant and efficient solution.

By understanding how different algorithms utilize queues, we can appreciate their versatility and importance in computer science. So next time you encounter a problem that requires organizing elements in a specific order, consider utilizing the power of queues!