Name		Name	Last commit message	Last commit date
parent directory ..
README.md		README.md
deque.cpp		deque.cpp
implementationOfQueueUsingLinkedList.cpp		implementationOfQueueUsingLinkedList.cpp
implementationOfQueuesUsingArrays.cpp		implementationOfQueuesUsingArrays.cpp
queue.cpp		queue.cpp
queueFromStackPushEfficient.cpp		queueFromStackPushEfficient.cpp
reverseElementsOfQueue.cpp		reverseElementsOfQueue.cpp

README.md

Introduction

Queue is a data structure that supports FIFO (First In First Out) or FCFS (First Come First Serve).
It is a linear data structure.
Example: Queue of people standing outside ATM.

Types of Operations on Queues

enqueue(): This operation will help us to add a new element in the queue.
dequeue(): This operation will help us to remove a new element in the queue.
isFull(): This operation will help us know if a queue is full or not.
isEmpty(): This operation will help us know if a queue is empty or not.
front(): This operation will give us the element which came first.
size(): This operation will give us the size of the queue.

front: tracks the first element; back/rear: element gets added from the end

Types of Queues

Simple Queue: Element is added from the back and removed from front.
Priority Queue: Based on custom priority, element is at the front.
Circular Queue: Front and rear are connected.
Double Ended Queue/Deque: Addition and removal of elements can be done from both sides.

Implementation of Queues

By using Array
By using Linked List

Advantage of Array Implementation of Queues

Array can manage data easily.

Disadvantage of Array Implementation of Queues

It is not space efficient.

Deque

In normal queues, back is responsible for addition of elements and front is responsible for accessing front element as well as removal of element.
Deque stands for Double Ended Queue.
We can add/remove elements from both front and back sides.
It is used to implement stack (by default).

Queues Questions