Data Structure and Types

 

data structure and its types.

What are Data Structures?

Data structure is a storage that is used to store and organize data. It is a way of arranging data on a computer so that it can be accessed and updated efficiently.

Depending on your requirement and project, it is important to choose the right data structure for your project. For example, if you want to store data sequentially in the memory, then you can go for the Array data structure.

Array data Structure Representation

Note: Data structure and data types are slightly different. Data structure is the collection of data types arranged in a specific order.

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Types of Data Structure

Basically, data structures are divided into two categories:

·         Linear data structure

·         Non-linear data structure

Let's learn about each type in detail.

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Linear data structures

In linear data structures, the elements are arranged in sequence one after the other. Since elements are arranged in particular order, they are easy to implement.

However, when the complexity of the program increases, the linear data structures might not be the best choice because of operational complexities.

Popular linear data structures are:

1. Array Data Structure

In an array, elements in memory are arranged in continuous memory. All the elements of an array are of the same type. And, the type of elements that can be stored in the form of arrays is determined by the programming language.

To learn more, visit Java Array.

An array with each element represented by an index

2. Stack Data Structure

In stack data structure, elements are stored in the LIFO principle. That is, the last element stored in a stack will be removed first.

It works just like a pile of plates where the last plate kept on the pile will be removed first. To learn more, visit Stack Data Structure.

In a stack, operations can be perform only from one end (top here).

3. Queue Data Structure

Unlike stack, the queue data structure works in the FIFO principle where first element stored in the queue will be removed first.

It works just like a queue of people in the ticket counter where first person on the queue will get the ticket first. To learn more, visit Queue Data Structure.
 

In a queue, addition and removal are performed from separate ends.

4. Linked List Data Structure

In linked list data structure, data elements are connected through a series of nodes. And, each node contains the data items and address to the next node.

To learn more, visit Linked List Data Structure.
 

A linked list

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Non linear data structures

Unlike linear data structures, elements in non-linear data structures are not in any sequence. Instead they are arranged in a hierarchical manner where one element will be connected to one or more elements.

Non-linear data structures are further divided into graph and tree based data structures.

1. Graph Data Structure

In graph data structure, each node is called vertex and each vertex is connected to other vertices through edges.

To learn more, visit Graph Data Structure.

Graph data structure example

Popular Graph Based Data Structures:

·         Spanning Tree and Minimum Spanning Tree

·         Strongly Connected Components

·         Adjacency Matrix

·         Adjacency List

2. Trees Data Structure

Similar to a graph, a tree is also a collection of vertices and edges. However, in tree data structure, there can only be one edge between two vertices.

To learn more, visit Tree Data Structure.

Tree data structure example

Popular Tree based Data Structure

·         Binary Tree

·         Binary Search Tree

·         AVL Tree

·         B-Tree

·         B+ Tree

·         Red-Black Tree

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Linear Vs Non-linear Data Structures

Now that we know about linear and non-linear data structures, let's see the major differences between them.

Linear Data Structures	Non Linear Data Structures
The data items are arranged in sequential order, one after the other.	The data items are arranged in non-sequential order (hierarchical manner).
All the items are present on the single layer.	The data items are present at different layers.
It can be traversed on a single run. That is, if we start from the first element, we can traverse all the elements sequentially in a single pass.	It requires multiple runs. That is, if we start from the first element it might not be possible to traverse all the elements in a single pass.
The memory utilization is not efficient.	Different structures utilize memory in different efficient ways depending on the need.
The time complexity increase with the data size.	Time complexity remains the same.
Example: Arrays, Stack, Queue	Example: Tree, Graph, Map

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Why Data Structure?

Knowledge about data structures help you understand the working of each data structure. And, based on that you can select the right data structures for your project.

This helps you write memory and time efficient code.

 

4.3.0 ASSOCIATE PROFESSOR A Master’s Degree with at least 55% marks with 5 Yrs Of Experience (or an equivalent grade in a point scale wherever grading system is followe

concern all engineering courses with minimum (M.Tech) aggregation is required for a lecturer job in almost all top colleges 

 M.TECH is the entry point , no base degree , regarding underlying degree no hard and fast rule

MCA, MSc grads allowed to teach in ENGG colleges: AICTE

https://timesofindia.indiatimes.com › indore › articleshow

15-Jun-2016 — MCA, MSc grads allowed to teach in engg colleges: AICTE ... who have finished ME or MTech or PhD in Computer Science/IT after acquiring MCA,

Assistant Professors (16 hours) and Associate Professors/Professors (14 hours) by MHRD to UGC. WORKLOADS i.e one subject to 2 sections, or 2 different subjects to different semisters

 Press Information Bureau

Government of India
Ministry of Human Resource Development
26-May-2016 20:03 IST

Ministry of HRD directs UGC to amend regulations regarding workload of teachers.

The Ministry of Human Resource Development (MHRD) has reviewed the recent amendment to the UGC (Minimum Qualifications for appointment of teachers and other academic staff in universities and colleges and measures for the maintenance of standards in higher education) Regulations, 2010.

Consequent on the review, the Ministry has issued a direction to the UGC, under Section 20(1) of the UGC Act, 1956, to undertake amendments in the Regulation. After these amendments are carried out, the position regarding workload will be as follows:-

(i) In the UGC (Minimum Qualifications for appointment of teachers and other academic staff in universities and colleges and measures for the maintenance of standards in higher education) Regulations, 2010, the overall workload of Assistant Professors and Associate Professors/Professors in full employment was prescribed to be not less than 40 hours a week for 180 teaching days. This workload remains unchanged, even with the amended Regulation.

(ii) The direct teaching-learning hours to be devoted by Assistant Professors (16 hours) and Associate Professors/Professors (14 hours) too will remain unchanged, as a consequence of the direction from the MHRD and subsequent notification by the UGC.

In consonance with established academic and teaching traditions, and with a view to reinforcing a student-centric and caring approach, teachers are encouraged to work with students, beyond the structure of classroom teaching. Indicatively, this could entail mentoring, guiding and counselling students. In particular teachers would be the best placed to identify and address the needs of students who may be differently-abled, or require assistance to improve their academic performance, or to overcome a disadvantage. There are no prescribed hours for such efforts, measured either in weeks or months. While they will not be included in the calculation of the API scores, these are nevertheless important and significant activities that could be carried out by teachers.

Teachers were required to allocate 6 additional hours per week, beyond the direct teaching-learning hours, on research. These hours can now be also utilized for tutorials/remedial classes/seminars/administrative responsibilities/ innovation and updating of course contents.

There will be no increase in the workload of teachers, after the amendments, in comparison with the workload prescribed earlier.

D.RAMANJANEYULU , M.C.A(A.U), M.TECH(JNTUCEH) , (P.hD),MISTE, AssociateProfessor & HEAD. PUBLICISED, AUTHENTICATED, TESTAMONIAL

 

Associate Professor RAMU @CLX, with ARUN KANDOOR HYD, at COLLEGE OF ENGINEERING & TECHONOLOGY, MTU UNIVERSITY, FACULTIE OF MTU

 

DAYINABOYINA AARNA , TIRUPATI,AP,INDIA. with AssocProf RAMU@DAYINABOYINA

 

 

What is Inter Process Communication?

In general, Inter Process Communication is a type of mechanism usually provided by the operating system (or OS). The main aim or goal of this mechanism is to provide communications in between several processes. In short, the intercommunication allows a process letting another process know that some event has occurred.

Let us now look at the general definition of inter-process communication, which will explain the same thing that we have discussed above.

Definition

"Inter-process communication is used for exchanging useful information between numerous threads in one or more processes (or programs)."

To understand inter process communication, you can consider the following given diagram that illustrates the importance of inter-process communication:

Role of Synchronization in Inter Process Communication

It is one of the essential parts of inter process communication. Typically, this is provided by interprocess communication control mechanisms, but sometimes it can also be controlled by communication processes.

These are the following methods that used to provide the synchronization:

1. Mutual Exclusion
2. Semaphore
3. Barrier
4. Spinlock

Mutual Exclusion:-

It is generally required that only one process thread can enter the critical section at a time. This also helps in synchronization and creates a stable state to avoid the race condition.

Semaphore:-

Semaphore is a type of variable that usually controls the access to the shared resources by several processes. Semaphore is further divided into two types which are as follows:

1. Binary Semaphore
2. Counting Semaphore

Barrier:-

A barrier typically not allows an individual process to proceed unless all the processes does not reach it. It is used by many parallel languages, and collective routines impose barriers.

Spinlock:-

Spinlock is a type of lock as its name implies. The processes are trying to acquire the spinlock waits or stays in a loop while checking that the lock is available or not. It is known as busy waiting because even though the process active, the process does not perform any functional operation (or task).

Approaches to Interprocess Communication

We will now discuss some different approaches to inter-process communication which are as follows:

These are a few different approaches for Inter- Process Communication:

1. Pipes
2. Shared Memory
3. Message Queue
4. Direct Communication
5. Indirect communication
6. Message Passing
7. FIFO

To understand them in more detail, we will discuss each of them individually.

Pipe:-

The pipe is a type of data channel that is unidirectional in nature. It means that the data in this type of data channel can be moved in only a single direction at a time. Still, one can use two-channel of this type, so that he can able to send and receive data in two processes. Typically, it uses the standard methods for input and output. These pipes are used in all types of POSIX systems and in different versions of window operating systems as well.

Shared Memory:-

It can be referred to as a type of memory that can be used or accessed by multiple processes simultaneously. It is primarily used so that the processes can communicate with each other. Therefore the shared memory is used by almost all POSIX and Windows operating systems as well.

Message Queue:-

In general, several different messages are allowed to read and write the data to the message queue. In the message queue, the messages are stored or stay in the queue unless their recipients retrieve them. In short, we can also say that the message queue is very helpful in inter-process communication and used by all operating systems.

To understand the concept of Message queue and Shared memory in more detail, let's take a look at its diagram given below:

Message Passing:-

It is a type of mechanism that allows processes to synchronize and communicate with each other. However, by using the message passing, the processes can communicate with each other without restoring the hared variables.

Usually, the inter-process communication mechanism provides two operations that are as follows:

• send (message)
• received (message)

Note: The size of the message can be fixed or variable.

Direct Communication:-

In this type of communication process, usually, a link is created or established between two communicating processes. However, in every pair of communicating processes, only one link can exist.

Indirect Communication

Indirect communication can only exist or be established when processes share a common mailbox, and each pair of these processes shares multiple communication links. These shared links can be unidirectional or bi-directional.

FIFO:-

It is a type of general communication between two unrelated processes. It can also be considered as full-duplex, which means that one process can communicate with another process and vice versa.

Some other different approaches

• Socket:-

It acts as a type of endpoint for receiving or sending the data in a network. It is correct for data sent between processes on the same computer or data sent between different computers on the same network. Hence, it used by several types of operating systems.

• File:-

A file is a type of data record or a document stored on the disk and can be acquired on demand by the file server. Another most important thing is that several processes can access that file as required or needed.

• Signal:-

As its name implies, they are a type of signal used in inter process communication in a minimal way. Typically, they are the massages of systems that are sent by one process to another. Therefore, they are not used for sending data but for remote commands between multiple processes.

Usually, they are not used to send the data but to remote commands in between several processes.

Why we need interprocess communication?

There are numerous reasons to use inter-process communication for sharing the data. Here are some of the most important reasons that are given below:

• It helps to speedup modularity
• Computational
• Privilege separation
• Convenience
• Helps operating system to communicate with each other and synchronize their actions as well.

Note: IPC cannot be considered a solution to all problems but what is important is that it does its job very well.