What is Double Ended Queue with example?

Deque is a double-ended queue that allows us to add/remove elements from both the ends i.e. front and rear, of the queue. Deque can be implemented using arrays or linked lists. In Java, we have a Deque interface that is inherited from the queue interface to implement Deque.

What are the Double Ended Queue operations?

A deque, also known as a double-ended queue, is an ordered collection of items similar to the queue. It has two ends, a front and a rear, and the items remain positioned in the collection. In a sense, this hybrid linear structure provides all the capabilities of stacks and queues in a single data structure.

How do you implement a Double Ended Queue?

Implementation of Deque using circular array

1. Operations on Deque:
2. insetFront(): Adds an item at the front of Deque.
3. insertRear(): Adds an item at the rear of Deque.
4. deleteFront(): Deletes an item from front of Deque.
5. deleteRear(): Deletes an item from rear of Deque.
6. getFront(): Gets the front item from queue.

How do you create a simple queue with a Double Ended Queue?

Insert Elements at back

1. If the queue is empty then intialize front and rear to 0. Both will point to the first element.
2. Else we increment rear and insert the element. Since we are using circular array, we have to keep in mind that if rear is equal to SIZE-1 then instead of increasing it by 1 we make it equal to 0.

What are the advantages of double ended queue?

With double ended queues, you are able to remove and add items from both the front and the back of the queue. In a queue, you can only add data to the back and remove it from the front.

What is disadvantage of linear queue?

A queue works like the line you wait in. In a linear queue, the traversal through the queue is possible only once,i.e.,once an element is deleted, we cannot insert another element in its position. This disadvantage of a linear queue is overcome by a circular queue, thus saving memory.

What is the advantage of doubly ended queue?

Why do you need a double ended queue?

Applications of Deque: Since Deque supports both stack and queue operations, it can be used as both. Also, the problems where elements need to be removed and or added both ends can be efficiently solved using Deque.

What are the advantages of priority queue?

A priority queue is typically implemented using Heap data structure. Applications: Dijkstra’s Shortest Path Algorithm using priority queue: When the graph is stored in the form of adjacency list or matrix, priority queue can be used to extract minimum efficiently when implementing Dijkstra’s algorithm.

What is the problem with linear queue?

The problem that arises with the linear queue is that if some empty cells occur at the beginning of the queue then we cannot insert new element at the empty space as the rear cannot be further incremented.

How is a deque a double ended queue?

Deque or Double Ended Queue is a type of queue in which insertion and removal of elements can either be performed from the front or the rear. Thus, it does not follow FIFO rule (First In First Out). In this deque, input is restricted at a single end but allows deletion at both the ends.

What are the basic operations of dequeue in C + +?

C++ Server Side Programming Programming Dequeue or Double Ended Queue is a generalized version of Queue data structure that allows insert and delete at both ends. Some basic operations of dequeue are − insert_at_beg (): inserts an item at the front of Dequeue.

What does the word dequeue mean in C?

What is Dequeue? The word dequeue is short form of double ended queue. In a dequeue, insertion as well as deletion can be carried out either at the rear end or the front end. A C program is given below which shows how various operations can be performed on a double ended queue represented by circular array.

Why is a double ended queue called a head tail linked list?

It is also known as a head-tail linked list because elements can be added to or removed from either the front (head) or the back (tail) end. However, no element can be added and deleted from the middle. There are two variants of a double-ended queue.