The document discusses different queue data structures, including their operations, implementations, and uses. It covers standard FIFO queues as well as priority queues, circular queues, and double-ended queues. Standard queue operations include enqueue, dequeue, peek, isempty, and isfull. Circular queues reuse space after reaching the end to avoid overflow. Priority queues order elements by priority level rather than insertion order. C code examples are provided for array-based standard and circular queue implementations.
This document discusses queues as a data structure. Some key points:
- Queues follow the FIFO (first in, first out) principle and have two main operations - enqueue to insert at the rear, and dequeue to remove from the front.
- Queues can be implemented using arrays or linked lists. Array implementation uses front and rear pointers to track the first and last elements while linked list uses pointers between nodes.
- Common applications of queues include task scheduling, disk I/O handling, media playback lists, call centers, and simulation of waiting lines where the first entry is the first to be served.
An ordered collection of items from which items may be deleted from one end called the front and into which items may be inserted from other end called rear is known as Queue.
It is a linear data structure.
It is called the First In First Out (FIFO) list. Since in queue, the first element will be the first element out.
Queue is an abstract data structure, somewhat similar to Stacks. Unlike stacks, a queue is open at both its ends. One end is always used to insert data (enqueue) and the other is used to remove data (dequeue). Queue follows First-In-First-Out methodology, i.e., the data item stored first will be accessed first.
The document discusses different types of queues, including simple, circular, priority, and double-ended queues. It describes the basic queue operations of enqueue and dequeue, where new elements are added to the rear of the queue and existing elements are removed from the front. Circular queues are more memory efficient than linear queues by connecting the last queue element back to the first, forming a circle. Priority queues remove elements based on priority rather than order of insertion. Double-ended queues allow insertion and removal from both ends. Common applications of queues include CPU and disk scheduling, synchronization between asynchronous processes, and call center phone systems.
Queue is an abstract data structure, somewhat similar to Stacks. Unlike stacks, a queue is open at both its ends. One end is always used to insert data (enqueue) and the other is used to remove data (dequeue). Queue follows First-In-First-Out methodology, i.e., the data item stored first will be accessed first.
The document discusses different types of queues, including simple queue, priority queue, circular queue, and dequeue. It describes the basic queue operations of enqueue and dequeue. Enqueue adds an element to the rear of the queue while dequeue removes an element from the front. Circular queues improve efficiency by connecting the rear to the front, allowing insertion and removal from any position. Priority queues remove elements based on priority rather than order of insertion. Queues are useful for CPU and disk scheduling, synchronization between processes, and applications like call centers.
This document discusses queues and their applications. It begins by defining queues as first-in, first-out (FIFO) data structures and describes how they can be implemented using arrays or linked lists. Common applications of queues include I/O buffering, job scheduling, and round-robin threading. The document also covers double-ended queues (deques), priority queues, and their implementations and applications.
A queue is a linear data structure that follows the First In First Out (FIFO) principle, where elements are added to the rear of the queue and removed from the front. Elements can be added using the enqueue operation and removed using the dequeue operation. A queue can be implemented using an array or linked list. A circular queue was introduced to prevent wasted memory when the rear reaches the end of the array. Priority queues order elements by priority when removing them, with higher priority elements served first.
This document discusses queues, including:
1. Queues follow a First-In First-Out (FIFO) methodology where the first item stored is the first item accessed.
2. Queues can be implemented using arrays or linked lists, with two pointers - a front pointer and rear pointer - to keep track of the first and last elements.
3. The basic queue operations are enqueue, which adds an item to the rear, and dequeue, which removes an item from the front.
A queue is a first-in, first-out (FIFO) data structure where elements are inserted at the rear and deleted from the front. There are two common implementations - a linear array implementation where the front and rear indices are incremented as elements are added/removed, and a circular array implementation where the indices wrap around to avoid unused space. Queues have applications in printing, scheduling, and call centers where requests are handled in the order received.
The document discusses different data structures including queues, deques, and priority queues. It defines queues as FIFO lists where elements are inserted at the rear and deleted from the front. Deques allow insertion and deletion from both ends. Priority queues store elements according to priority level, with highest priority elements removed first. Array and linked list implementations of these structures are presented along with common operations like insertion, deletion, and traversal. Applications include job scheduling, simulation events, emergency patients, and background task prioritization.
Queue is a linear data structure where elements are inserted at one end called the rear and deleted from the other end called the front. It follows the FIFO (first in, first out) principle. Queues can be implemented using arrays or linked lists. In an array implementation, elements are inserted at the rear and deleted from the front. In a linked list implementation, nodes are added to the rear and removed from the front using front and rear pointers. There are different types of queues including circular queues, double-ended queues, and priority queues.
A queue is a first-in, first-out (FIFO) collection where elements are inserted at the rear and deleted from the front. A circular queue solves the problem of overflow by making the queue circular, so the rear wraps around to the front when full. Operations on a circular queue include insertion, which adds elements to the rear until the queue is full and the rear wraps to the front, and deletion, which removes elements from the front. A priority queue processes elements according to priority, with higher priority elements removed before lower priority ones.
The document describes different types of queues as data structures. A queue is a first-in, first-out (FIFO) data structure where elements are added to the rear and removed from the front. The document discusses linear (simple) queues, circular queues, double-ended queues, and priority queues. It provides algorithms and examples for insert and delete operations on each type of queue.
Queue data structures and operation on data structuresmuskans14
This document discusses queues, which are ordered collections where items are inserted at the rear and removed from the front. There are two main operations: enqueue, which inserts an item at the rear, and dequeue, which removes an item from the front. Queues can be implemented using arrays or pointers. The key types are simple, circular, priority, and dequeue queues. Memory representation uses a linear array and front/rear pointers. Enqueue increments rear and inserts at that index, while dequeue removes from front and increments front if not last element. Queues have applications in operating systems, scheduling, and simulation.
The document discusses different types of queues, including simple, circular, priority, and double-ended queues. It describes the basic queue operations of enqueue and dequeue, where new elements are added to the rear of the queue and existing elements are removed from the front. Circular queues are more memory efficient than linear queues by connecting the last queue element back to the first, forming a circle. Priority queues remove elements based on priority rather than order of insertion. Double-ended queues allow insertion and removal from both ends. Common applications of queues include CPU and disk scheduling, synchronization between asynchronous processes, and call center phone systems.
Queue is an abstract data structure, somewhat similar to Stacks. Unlike stacks, a queue is open at both its ends. One end is always used to insert data (enqueue) and the other is used to remove data (dequeue). Queue follows First-In-First-Out methodology, i.e., the data item stored first will be accessed first.
The document discusses different types of queues, including simple queue, priority queue, circular queue, and dequeue. It describes the basic queue operations of enqueue and dequeue. Enqueue adds an element to the rear of the queue while dequeue removes an element from the front. Circular queues improve efficiency by connecting the rear to the front, allowing insertion and removal from any position. Priority queues remove elements based on priority rather than order of insertion. Queues are useful for CPU and disk scheduling, synchronization between processes, and applications like call centers.
This document discusses queues and their applications. It begins by defining queues as first-in, first-out (FIFO) data structures and describes how they can be implemented using arrays or linked lists. Common applications of queues include I/O buffering, job scheduling, and round-robin threading. The document also covers double-ended queues (deques), priority queues, and their implementations and applications.
A queue is a linear data structure that follows the First In First Out (FIFO) principle, where elements are added to the rear of the queue and removed from the front. Elements can be added using the enqueue operation and removed using the dequeue operation. A queue can be implemented using an array or linked list. A circular queue was introduced to prevent wasted memory when the rear reaches the end of the array. Priority queues order elements by priority when removing them, with higher priority elements served first.
This document discusses queues, including:
1. Queues follow a First-In First-Out (FIFO) methodology where the first item stored is the first item accessed.
2. Queues can be implemented using arrays or linked lists, with two pointers - a front pointer and rear pointer - to keep track of the first and last elements.
3. The basic queue operations are enqueue, which adds an item to the rear, and dequeue, which removes an item from the front.
A queue is a first-in, first-out (FIFO) data structure where elements are inserted at the rear and deleted from the front. There are two common implementations - a linear array implementation where the front and rear indices are incremented as elements are added/removed, and a circular array implementation where the indices wrap around to avoid unused space. Queues have applications in printing, scheduling, and call centers where requests are handled in the order received.
The document discusses different data structures including queues, deques, and priority queues. It defines queues as FIFO lists where elements are inserted at the rear and deleted from the front. Deques allow insertion and deletion from both ends. Priority queues store elements according to priority level, with highest priority elements removed first. Array and linked list implementations of these structures are presented along with common operations like insertion, deletion, and traversal. Applications include job scheduling, simulation events, emergency patients, and background task prioritization.
Queue is a linear data structure where elements are inserted at one end called the rear and deleted from the other end called the front. It follows the FIFO (first in, first out) principle. Queues can be implemented using arrays or linked lists. In an array implementation, elements are inserted at the rear and deleted from the front. In a linked list implementation, nodes are added to the rear and removed from the front using front and rear pointers. There are different types of queues including circular queues, double-ended queues, and priority queues.
A queue is a first-in, first-out (FIFO) collection where elements are inserted at the rear and deleted from the front. A circular queue solves the problem of overflow by making the queue circular, so the rear wraps around to the front when full. Operations on a circular queue include insertion, which adds elements to the rear until the queue is full and the rear wraps to the front, and deletion, which removes elements from the front. A priority queue processes elements according to priority, with higher priority elements removed before lower priority ones.
The document describes different types of queues as data structures. A queue is a first-in, first-out (FIFO) data structure where elements are added to the rear and removed from the front. The document discusses linear (simple) queues, circular queues, double-ended queues, and priority queues. It provides algorithms and examples for insert and delete operations on each type of queue.
Queue data structures and operation on data structuresmuskans14
This document discusses queues, which are ordered collections where items are inserted at the rear and removed from the front. There are two main operations: enqueue, which inserts an item at the rear, and dequeue, which removes an item from the front. Queues can be implemented using arrays or pointers. The key types are simple, circular, priority, and dequeue queues. Memory representation uses a linear array and front/rear pointers. Enqueue increments rear and inserts at that index, while dequeue removes from front and increments front if not last element. Queues have applications in operating systems, scheduling, and simulation.
May 2025: Top 10 Cited Articles in Software Engineering & Applications Intern...sebastianku31
The International Journal of Software Engineering & Applications (IJSEA) is a bi-monthly open access peer-reviewed journal that publishes articles which contribute new results in all areas of the Software Engineering & Applications. The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on understanding Modern software engineering concepts & establishing new collaborations in these areas.
May 2025 - Top 10 Read Articles in Artificial Intelligence and Applications (...gerogepatton
The International Journal of Artificial Intelligence & Applications (IJAIA) is a bi monthly open access peer-reviewed journal that publishes articles which contribute new results in all areas of the Artificial Intelligence & Applications (IJAIA). It is an international journal intended for professionals and researchers in all fields of AI for researchers, programmers, and software and hardware manufacturers. The journal also aims to publish new attempts in the form of special issues on emerging areas in Artificial Intelligence and applications.
Civil engineering faces significant challenges from expansive soils, which can lead to structural damage. This study aims to optimize subtractive clustering and Fuzzy C-Mean Clustering (FCM) models for the most accurate prediction of swelling percentage in expansive soils. Two ANFIS models were developed, namely the FIS1S model using subtractive clustering and the FIS2S model utilizing the FCM algorithm. Due to the MATLAB graphical user interface's limitation on the number of membership functions, the coding approach was employed to develop the ANFIS models for optimal prediction accuracy and problem-solving time. So, two programs were created to determine the optimal influence radius for the FIS1S model and the number of membership functions for the FIS2S model to achieve the highest prediction accuracy. The ANFIS models have demonstrated their highest predictive ability in predicting swelling percentage, thanks to the optimization of membership functions and cluster centers. The developed programs also showed excellent performance and can be potentially applied to optimize subtractive clustering and FCM models in accurately modeling various engineering aspects.
Third Review PPT that consists of the project d etails like abstract.Sowndarya6
CyberShieldX is an AI-driven cybersecurity SaaS web application designed to provide automated security analysis and proactive threat mitigation for business websites. As cyber threats continue to evolve, traditional security tools like OpenVAS and Nessus require manual configurations and lack real-time automation. CyberShieldX addresses these limitations by integrating AI-powered vulnerability assessment, intrusion detection, and security maintenance services. Users can analyze their websites by simply submitting a URL, after which CyberShieldX conducts an in-depth vulnerability scan using advanced security tools such as OpenVAS, Nessus, and Metasploit. The system then generates a detailed report highlighting security risks, potential exploits, and recommended fixes. Premium users receive continuous security monitoring, automatic patching, and expert assistance to fortify their digital infrastructure against emerging threats. Built on a robust cloud infrastructure using AWS, Docker, and Kubernetes, CyberShieldX ensures scalability, high availability, and efficient security enforcement. Its AI-driven approach enhances detection accuracy, minimizes false positives, and provides real-time security insights. This project will cover the system's architecture, implementation, and its advantages over existing security solutions, demonstrating how CyberShieldX revolutionizes cybersecurity by offering businesses a smarter, automated, and proactive defense mechanism against ever-evolving cyber threats.
Rearchitecturing a 9-year-old legacy Laravel application.pdfTakumi Amitani
An initiative to re-architect a Laravel legacy application that had been running for 9 years using the following approaches, with the goal of improving the system’s modifiability:
・Event Storming
・Use Case Driven Object Modeling
・Domain Driven Design
・Modular Monolith
・Clean Architecture
This slide was used in PHPxTKY June 2025.
https://phpxtky.connpass.com/event/352685/
This study will provide the audience with an understanding of the capabilities of soft tools such as Artificial Neural Networks (ANN), Support Vector Regression (SVR), Model Trees (MT), and Multi-Gene Genetic Programming (MGGP) as a statistical downscaling tool. Many projects are underway around the world to downscale the data from Global Climate Models (GCM). The majority of the statistical tools have a lengthy downscaling pipeline to follow. To improve its accuracy, the GCM data is re-gridded according to the grid points of the observed data, standardized, and, sometimes, bias-removal is required. The current work suggests that future precipitation can be predicted by using precipitation data from the nearest four grid points as input to soft tools and observed precipitation as output. This research aims to estimate precipitation trends in the near future (2021-2050), using 5 GCMs, for Pune, in the state of Maharashtra, India. The findings indicate that each one of the soft tools can model the precipitation with excellent accuracy as compared to the traditional method of Distribution Based Scaling (DBS). The results show that ANN models appear to give the best results, followed by MT, then MGGP, and finally SVR. This work is one of a kind in that it provides insights into the changing monsoon season in Pune. The anticipated average precipitation levels depict a rise of 300–500% in January, along with increases of 200-300% in February and March, and a 100-150% increase for April and December. In contrast, rainfall appears to be decreasing by 20-30% between June and September.
International Journal of Distributed and Parallel systems (IJDPS)samueljackson3773
The growth of Internet and other web technologies requires the development of new
algorithms and architectures for parallel and distributed computing. International journal of
Distributed and parallel systems is a bimonthly open access peer-reviewed journal aims to
publish high quality scientific papers arising from original research and development from
the international community in the areas of parallel and distributed systems. IJDPS serves
as a platform for engineers and researchers to present new ideas and system technology,
with an interactive and friendly, but strongly professional atmosphere.
Call For Papers - International Journal on Natural Language Computing (IJNLC)kevig
Natural Language Processing is a programmed approach to analyze text that is based on both a
set of theories and a set of technologies. This forum aims to bring together researchers who have
designed and build software that will analyze, understand, and generate languages that humans use
naturally to address computers.
Call For Papers - International Journal on Natural Language Computing (IJNLC)kevig
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The Queue in Data structure and algorithm
1. Module II
Queue
Basic Concept of Queue
Queue:
A Queue is defined as a linear data structure that is open at both ends and the operations are performed
in First In First Out (FIFO) order.
Applications of Queue :
1.Queues are widely used as waiting lists for a single shared resource like printer, disk, CPU.
2.Queues are used in asynchronous transfer of data (where data is not being transferred at the same rate
between two processes) for eg. pipes, file IO, sockets.
3.Queues are used as buffers in most of the applications like MP3 media player, CD player, etc.
4.Queue are used to maintain the play list in media players in order to add and remove the songs from the
play-list.
2. Module II
Queue
Basic Concept of Queue
FIFO Principle of Queue:
•A Queue is like a line waiting to purchase tickets, where the first person in line is the first
person served. (i.e. First come first serve).
•Position of the entry in a queue ready to be served, that is, the first entry that will be
removed from the queue, is called the front of the queue(sometimes, head of the queue),
similarly, the position of the last entry in the queue, that is, the one most recently added, is
called the rear (or the tail) of the queue. See the below figure
3. Module II
Queue
Basic Concept of Queue
Queue Representation:
Like stacks, Queues can also be represented in an array: In this representation, the Queue is
implemented using the array. Variables used in this case are
•Queue: the name of the array storing queue elements.
•Front: the index where the first element is stored in the array representing the queue.
•Rear: the index where the last element is stored in an array representing the queue.
We will be implementing the Queue data structure using an array in C+
+,Java and list in Python.
Characteristics of Queue:
•Queue can handle multiple data.
•We can access both ends.
•They are fast and flexible.
4. Module II
Queue
Queue as an ADT
Queue as an ADT:
The queue abstract data type is defined by the following structure and
operations. A queue is structured, as described above, as an ordered
collection of items which are added at one end, called the “rear,” and
removed from the other end, called the “front.” Queues maintain a FIFO
ordering property.
• Queue() : creates a new queue that is empty. It needs no parameters and returns an empty queue.
• enqueue(item): adds a new item to the rear of the queue. It needs the item and returns nothing.
• dequeue(): removes the front item from the queue. It needs no parameters and returns the item.
The queue is modified.
• isEmpty(): tests to see whether the queue is empty. It needs no parameters and returns a Boolean
value.
• size(): returns the number of items in the queue. It needs no parameters and returns an integer.
5. Module II
Queue
Types of Queue
Types of Queue :
There are four different types of queue that are listed as follows -
oSimple Queue or Linear Queue
oCircular Queue
oPriority Queue
oDouble Ended Queue (or Deque)
Simple Queue or Linear Queue :
In Linear Queue, an insertion takes place from one end while the deletion occurs from another end. The
end at which the insertion takes place is known as the rear end, and the end at which the deletion takes
place is known as front end. It strictly follows the FIFO rule.
The major drawback of using a linear Queue is that insertion is done only from the rear end. If the first
three elements are deleted from the Queue, we cannot insert more elements even though the space is
available in a Linear Queue. In this case, the linear Queue shows the overflow condition as the rear is
pointing to the last element of the Queue.
6. Module II
Queue
Types of Queue
Circular Queue :
In Circular Queue, all the nodes are represented as circular. It is similar to the linear Queue
except that the last element of the queue is connected to the first element. It is also known as
Ring Buffer, as all the ends are connected to another end. The representation of circular
queue is shown in the below image -
The drawback that occurs in a linear queue is overcome by using the circular queue. If the
empty space is available in a circular queue, the new element can be added in an empty
space by simply incrementing the value of rear. The main advantage of using the circular
queue is better memory utilization.
7. Module II
Queue
Types of Queue
Priority Queue:
It is a special type of queue in which the elements are arranged based on the priority. It is a
special type of queue data structure in which every element has a priority associated with it.
Suppose some elements occur with the same priority, they will be arranged according to the
FIFO principle. The representation of priority queue is shown in the below image -
Insertion in priority queue takes place based on the arrival, while deletion in the priority
queue occurs based on the priority. Priority queue is mainly used to implement the CPU
scheduling algorithms.
8. Module II
Queue
Types of Queue
Two types of priority queue : –
•Ascending priority queue - In ascending priority queue, elements can be inserted in
arbitrary order, but only smallest can be deleted first. Suppose an array with elements 7,
10,11,6 and 2 in the same order, so, insertion can be done with the same sequence, but the
order of deleting the elements is 2, 6, 7,10,11.
•Descending priority queue - In descending priority queue, elements can be inserted in
arbitrary order, but only the largest element can be deleted first. Suppose an array with
elements 8,6,10,9 and 7 in the same order, so, insertion can be done with the same sequence,
but the order of deleting the elements is 10,9,8,7,6.
9. Module II
Queue
Types of Queue
Deque (or, Double Ended Queue):
In Deque or Double Ended Queue, insertion and deletion can be done from both
ends of the queue either from the front or rear. It means that we can insert and
delete elements from both front and rear ends of the queue. Deque can be used as a
palindrome checker means that if we read the string from both ends, then the string
would be the same.
Deque can be used both as stack and queue as it allows the insertion and deletion
operations on both ends. Deque can be considered as stack because stack follows
the LIFO (Last In First Out) principle in which insertion and deletion both can be
performed only from one end. And in deque, it is possible to perform both insertion
and deletion from one end, and Deque does not follow the FIFO principle.
10. Module II
Queue
Types of Queue
Two types of deque :
•Input restricted deque - As the name implies, in input restricted queue, insertion operation
can be performed at only one end, while deletion can be performed from both ends.
•Output restricted deque - As the name implies, in output restricted queue, deletion
operation can be performed at only one end, while insertion can be performed from both
ends.
11. Module II
Queue
Operation
Operations performed on queue :
oEnqueue: The Enqueue operation is used to insert the element at the rear end of the queue.
It returns void.
oDequeue: It performs the deletion from the front-end of the queue. It also returns the
element which has been removed from the front-end. It returns an integer value.
oPeek: This is the third operation that returns the element, which is pointed by the front
pointer in the queue but does not delete it.
oQueue overflow (isfull): It shows the overflow condition when the queue is completely
full.
oQueue underflow (isempty): It shows the underflow condition when the Queue is empty,
i.e., no elements are in the Queue.
Ways to implement the queue:
•Implementation using array: The sequential allocation in a Queue can be implemented using an array.
•Implementation using Linked list: The linked list allocation in a Queue can be implemented using a
linked list.
12. Module II
Queue
Types of Queue
• Enqueue() Operation :
The enqueue() is a data manipulation operation that is used to insert elements into the stack. The following algorithm
describes the enqueue() operation in a simpler way.
Algorithm:
1 − START
2 – Check if the queue is full.
3 − If the queue is full, produce overflow error and exit.
4 − If the queue is not full, increment rear pointer to point the next empty space.
5 − Add data element to the queue location, where the rear is pointing.
6 − return success.
7 – END
13. Module II
Queue
Operation
• Dequeue() Operation:
The dequeue() is a data manipulation operation that is used to remove elements from the stack. The following algorithm
describes the dequeue() operation in a simpler way.
Algorithm:
1 – START
2 − Check if the queue is empty.
3 − If the queue is empty, produce underflow error and exit.
4 − If the queue is not empty, access the data where front is pointing.
5 − Increment front pointer to point to the next available data element.
6 − Return success.
7 – END
14. Module II
Queue
Operation
• peek() Operation:
The peek() is an operation which is used to retrieve the frontmost element in the queue, without deleting it. This
operation is used to check the status of the queue with the help of the pointer.
Algorithm:
1 – START
2 – Return the element at the front of the queue
3 – END
• isFull() Operation:
The isFull() operation verifies whether the stack is full.
Algorithm:
1 – START
2 – If the count of queue elements equals the queue size, return true
3 – Otherwise, return false
4 – END
• isEmpty() operation:
The isEmpty() operation verifies whether the stack is empty. This operation is used to check the status of the stack with
the help of top pointer.
Algorithm:
1 – START
2 – If the count of queue elements equals zero, return true
3 – Otherwise, return false
4 – END
15. Module II
Queue
Operation
Advantages of Queue:
•A large amount of data can be managed efficiently with ease.
•Operations such as insertion and deletion can be performed with ease as it
follows the first in first out rule.
•Queues are useful when a particular service is used by multiple consumers.
•Queues are fast in speed for data inter-process communication.
•Queues can be used in the implementation of other data structures.
Disadvantages of Queue:
•The operations such as insertion and deletion of elements from the middle are
time consuming.
•Limited Space.
•In a classical queue, a new element can only be inserted when the existing
elements are deleted from the queue.
•Searching an element takes O(N) time.
•Maximum size of a queue must be defined prior.
