What Is Simple Queue in Data Structure?
A queue is a fundamental data structure in computer science that follows the FIFO (First-In-First-Out) principle. In other words, the first element added to the queue will be the first one to be removed.
Queues are commonly used in various applications, including operating systems, network protocols, and simulations.
The Simple Queue
The simple queue is one of the simplest forms of a queue. It consists of a linear collection of elements where insertions can only occur at one end (rear) and removals can only occur at the other end (front).
This particular type of queue does not have a limited capacity and can dynamically grow as elements are added.
Operations on a Simple Queue
The simple queue supports two primary operations: enqueue and dequeue.
To enqueue an element means to insert it at the rear end of the queue.
The new element becomes the last element in the queue.
To dequeue an element means to remove it from the front end of the queue. The element that was added first will be removed.
These operations allow us to add elements to the queue and retrieve them in the order they were added.
The Implementation of Simple Queue
There are several ways to implement a simple queue, but one common approach is by using an array or a linked list. Both implementations have their advantages and disadvantages.
- Array Implementation:
- Linked List Implementation:
Using an array to implement a simple queue is straightforward. We keep track of the front and rear indices, and upon enqueueing or dequeueing, we update these indices accordingly.
However, this implementation has a fixed size and may require resizing if the queue becomes full.
Using a linked list to implement a simple queue allows for dynamic memory allocation. Each element in the queue is represented by a node that stores the element’s value and a reference to the next node. This implementation can grow as needed without any fixed size limitations.
Applications of Simple Queues
Simple queues find applications in numerous areas of computer science. Here are a few examples:
- Process Scheduling:
- Breadth-First Search (BFS):
- Printers and Network Buffers:
In operating systems, queues are used to manage processes waiting for execution.
The scheduler selects the process at the front of the queue for execution based on priority or other criteria.
The BFS algorithm uses a queue to traverse graphs efficiently. It explores all vertices at the current depth level before moving on to deeper levels.
In network protocols and printer spoolers, queues are used to store data packets or print jobs until they can be processed or forwarded.
In conclusion, a simple queue is an essential data structure that follows the FIFO principle. It allows elements to be enqueued at one end and dequeued at the other end.
Simple queues can be implemented using arrays or linked lists, each with its own advantages. They find applications in various areas, including process scheduling, graph traversal, and network protocols.