Queue (Computer Science)
Queue is a linear data structure in computer science which follows the FIFO (First In First Out) principle. It can be considered as an abstract data type, since it can be easily implemented using an array, linked list, or even a simple stack. Queue is used in various applications including but not limited to operating system task scheduling, communication protocols, and discrete event simulation.
A Queue can be divided into two sub-types based on its operational mechanism: Circular Queue and Priority Queue. A Circular Queue is a non-linear type of queue where an element is added at the end and taken out from the start. In a Priority Queue, elements are added at the end based on their priority.
In programming, Queues are usually implemented in C/C++, Java, and Python. A Queue is typically created with two methods: enqueue (to add an item) and dequeue (to remove an item). Other useful methods that can be implemented for a Queue include peek (to look at the item which will be dequeued next), size (to check the number of items in the Queue), isEmpty (to check if the Queue is empty), and isFull (to check if the Queue is full). The most commonly used Queue implementation is the doubly linked list, although arrays may also be used.
A Queue is used in many different applications including: in operating systems to manage tasks; in networks for congestion control; and in scheduling tasks in a multiprocessor system. They are also used as communication buffers in data transfer protocols, such as FTP and HTTP. Queues are also used for email sorting and storing, and sorting and finding data in databases.
Queue is a useful and simple data structure for many applications. It has many advantages over other linear data structures, such as being easy to implement and optimize as well as having better performance compared to other data structures.
