Aim: To study and implement Queue implementation using array.

Software Required:

Visual Studio

Theory:

A queue is a linear data structure that consists of elements arranged in a sequential order where one end is used to add elements, and another for removing them which results in the FIFO (First-In First-Out) order of operations.

The queue is a linear data structure that has the following properties:-

• It works on the principle of FIFO (First In First Out)
• It has mainly 2 pointers to perform operations: Front & Rear. The Rear is for insertion and the Front is for deletion
• It is a linear data structure that gives sequential one-way access to the elements. Even though we can implement it using an array, we cannot access any element through
• indices directly because access to elements is given only through the rear and front pointers.

Applications of Queue: Due to its FIFO nature, queue is a widely utilised data structure in a variety of real world applications :-

• Computer Science Fundamentals: its utilised in mostly the core operating system concepts like Job Scheduling Algorithms, Memory management for processing, basically putting the processes inside a queue so that they can be executed concurrently by the processor

• Algorithms: To store addresses of tree nodes, linked list nodes, and Graph Nodes BFS (Breadth First Search) etc.

• Real World Application: In a music or video player app you must've seen the option "Add to Queue" which is basically the Enqueue operation

Implemnetaion:

This concept was demonstrated using a singke code that shows queuing, dequeuing and enqueuing in C++

Algorithms:

Algorithm: Implement Queue using Array

1. Start
2. Define a class Queue with: An integer array arr[SIZE]. Two integer variables front and rear initialized to -1. Functions: enqueue(), dequeue(), and display().
3. Enqueue operation (enqueue(value))
   1. If rear == SIZE - 1, display "Queue Overflow!" and return.
   2. If front == -1, set front = 0.
   3. Increment rear and insert the value into arr[rear].
   4. Display confirmation message.
4. Dequeue operation (dequeue())
   1. If front == -1 OR front > rear, display "Queue Underflow!" and return.
   2. Display the element arr[front] being removed.
   3. Increment front.
5. Display operation (display())
   1. If front == -1 OR front > rear, display "Queue is empty".
   2. Otherwise, print all elements from arr[front] to arr[rear].
6. In main()
   1. Create an object q of class Queue.
   2. Perform enqueue, dequeue, and display operations to test queue behavior.
7. End

Conclusion:

Through the above code the concept of queuing and its applications was seen in C++.