# Data Structures: Question Set – 08

#### How do you check if a circular queue is full or empty?

To check if a circular queue is full, you can compare the rear and front pointers. If rear == (front – 1) % size, the queue is full. To check if the queue is empty, you can compare the front and rear pointers. If front == rear, the queue is empty.

#### What are some strategies for dealing with an overflowing circular queue?

When the rear pointer in a circular queue hits the end of the array and there is nowhere else for new elements to be added, an overflow occurs in the queue. We have two options for dealing with overflow: either we can expand the size of the array, or we can use a linked list to create a circular queue.

#### In a circular queue, how do you handle underflow when it occurs?

When the front pointer in a circular queue moves ahead of the rear pointer, this indicates that the queue is empty and is an instance of underflow. We have two options for dealing with underflow: first, we can check to see if the queue is empty before carrying out a dequeue operation, or second, we can make use of a sentinel value to signal an empty element in the queue.

#### It has been suggested that a circular queue may be created using a doubly linked list.

It is possible to create a circular queue by using a doubly linked list and pointing the final element of the list to the first element of the list and the first element of the list to the last element of the list.

#### What are some of the several ways a circular queue can be used?

Streaming data processing, network packet processing, and operating system task scheduling are all examples of applications that call for a buffer of a predetermined size. A circular queue can be employed in these kinds of applications.

#### What are the benefits of utilising a circular queue as opposed to a stack or a linked list?

Applications that need to quickly handle data streams or sequences can benefit from using a circular queue because it makes insertion and deletion operations more efficient from both ends of the queue. A linked list, on the other hand, requires additional pointer manipulation in order to do efficient insertion and deletion from both ends. A stack, on the other hand, is restricted to just being able to add and remove elements from a single end.

#### What are the most important functions that a priority queue performs?

Insert (which means to add an item that has a priority) and delete-max (to remove the element with the highest priority) are the two most important actions that a priority queue supports.

#### How is a priority queue implemented?

There are a variety of data structures that can be used to build a priority queue, including a binary heap, a Fibonacci heap, or a self-balancing binary search tree such as an AVL tree or a Red-Black tree. Another option is a Fibonacci heap.

#### When working with a priority queue, what is the time complexity of doing operations such as insert and delete-max?

Insert and delete-max actions in a priority queue might have varying degrees of time complexity depending on how the system is designed. The time complexity of an insert and delete-max operation in a binary heap implementation is O(log n), while the time complexity of an insert operation in a Fibonacci heap implementation is O(1), and the time complexity of a delete-max operation is O(log n).

#### What is the difference between a priority queue and a regular queue?

In a conventional queue, items are removed in accordance with the First-In-First-Out (FIFO) principle; however, in a priority queue, elements are removed depending on their priority rather than the order in which they arrived.