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rithesh rock  studying in kits college Innovation is often also viewed as the application of better solutions that meet new requirements, unarticulated needs, or existing market needs.[1] This is accomplished through more-effective products, processes, services, technologies, or business models that are readily available to markets, governments and society. The term "innovation" can be defined as something original and more effective and, as a consequence, new, that "breaks into" the market or society.[2] It is related to, but not the same as, invention,[3] as innovation is more apt to involve the practical implementation of an invention (i.e. new/improved ability) to make a meaningful impact in the market or society,[4] and not all innovations require an invention. Innovation is often manifested via the engineering process, when the problem being solved is of a technical or scientific nature. The opposite of innovation is exnovation.

While a novel device is often described as an innovation, in economics, management science, and other fields of practice and analysis, innovation is generally considered to be the result of a process that brings together various novel ideas in a way that they affect society. In industrial economics, innovations are created and found empirically from services to meet the growing consumer demand computer science student aboutComputer science is the study of the theory, experimentation, and engineering that form the basis for the design and use of computers. It is the scientific and practical approach to computation and its applications and the systematic study of the feasibility, structure, expression, and mechanization of the methodical procedures (or algorithms) that underlie the acquisition, representation, processing, storage, communication of, and access to information. An alternate, more succinct definition of computer science is the study of automating algorithmic processes that scale. A computer scientist specializes in the theory of computation and the design of computational systems.[1]

Its fields can be divided into a variety of theoretical and practical disciplines. Some fields, such as computational complexity theory (which explores the fundamental properties of computational and intractable problems), are highly abstract, while fields such as computer graphics emphasize real-world visual applications. Other fields still focus on challenges in implementing computation. For example, programming language theory considers various approaches to the description of computation, while the study of computer programming itself investigates various aspects of the use of programming language and complex systems. Human–computer interaction considers the challenges in making computers and computations useful, usable, and universally accessible to humans. Computing and technology Computer hacking, including: Hacker culture, activity within the computer programmer subculture Security hacker, someone who breaches defenses in a computer system Cybercrime Phone hacking, gaining unauthorized access to phones ROM hacking, the process of modifying a video game's program image There are two generally, similar and accepted meanings of the phrase personal computer (PC):

1) PC is short for personal computer or IBM PC. The first personal computer produced by IBM was called the PC, and increasingly the term PC came In recent years, the term PC has become more and more difficult to pin down. In general, though, it applies to any personal computer based on an Intel microprocessor, or on an Intel-compatible microprocessor. expert in the A blockchain,[1][2][3] originally block chain,[4][5] is a continuously growing list of records, called blocks, which are linked and secured using cryptography.[1][6] Each block typically contains a hash pointer as a link to a previous block,[6] a timestamp and transaction data.[7] By design, blockchains are inherently resistant to modification of the data. The Harvard Business Review describes it as "an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way."[8] For use as a distributed ledger, a blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without the alteration of all subsequent blocks, which requires collusion of the network majority.

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Blockchains are secure by design and are an example of a distributed computing system with high Byzantine fault tolerance. Decentralized consensus has therefore been achieved with a blockchain.[9] This makes blockchains potentially suitable for the recording of events, medical records,[10][11] and other records management activities, such as identity management,[12][13][14] transaction processing, documenting provenance, food traceability[15] or voting.[16]

The first blockchain was conceptualized in 2008 by an anonymous person or group known as Satoshi Nakamoto and implemented in 2009 as a core component of bitcoin where it serves as the public ledger for all transactions.[1] The invention of the blockchain for bitcoin made it the first digital currency to solve the double spending problem without the need of a trusted authority or central server. The bitcoin design has been the inspiration for other applications Description[edit source] A blockchain facilitates secure online transactions.[29][better source needed] A blockchain is a decentralized and distributed digital ledger that is used to record transactions across many computers so that the record cannot be altered retroactively without the alteration of all subsequent blocks and the collusion of the network.[1][30] This allows the participants to verify and audit transactions inexpensively.[31] They are authenticated by mass collaboration powered by collective self-interests.[32] The result is a robust workflow where participants' uncertainty regarding data security is marginal. The use of a blockchain removes the characteristic of infinite reproducibility from a digital asset. It confirms that each unit of value was transferred only once, solving the long-standing problem of double spending. Blockchains have been described as a value-exchange protocol.[21] This blockchain-based exchange of value can be completed more quickly, more safely and more cheaply than with traditional systems.[33] A blockchain can assign title rights because it provides a record that compels offer and acceptance.[1]

A blockchain database consists of two kinds of records: transactions and blocks.[1] Blocks hold batches of valid transactions that are hashed and encoded into a Merkle tree.[1] Each block includes the hash of the prior block in the blockchain, linking the two. The linked blocks form a chain.[1] This iterative process confirms the integrity of the previous block, all the way back to the original genesis block.[34] Some blockchains create a new block as frequently as every five seconds.[35]

Sometimes separate blocks can be produced concurrently, creating a temporary fork. In addition to a secure hash based history, any blockchain has a specified algorithm for scoring different versions of the history so that one with a higher value can be selected over others. Blocks not selected for inclusion in the chain are called orphan blocks.[34] Peers supporting the database have different versions of the history from time to time. They only keep the highest scoring version of the database known to them. Whenever a peer receives a higher scoring version (usually the old version with a single new block added) they extend or overwrite their own database and retransmit the improvement to their peers. There is never an absolute guarantee that any particular entry will remain in the best version of the history forever. Because blockchains are typically built to add the score of new blocks onto old blocks and because there are incentives to work only on extending with new blocks rather than overwriting old blocks, the probability of an entry becoming superseded goes down exponentially[36] as more blocks are built on top of it, eventually becoming very low.[1][37]:ch. 08[38] For example, in a blockchain using the proof-of-work system, the chain with the most cumulative proof-of-work is always considered the valid one by the network. There are a number of methods that can be used to demonstrate a sufficient level of computation. Within a blockchain the computation is carried out redundantly rather than in the traditional segregated and parallel manner.[39]

Decentralization[edit source] By storing data across its network, the blockchain eliminates the risks that come with data being held centrally.[1] The decentralized blockchain may use ad-hoc message passing and distributed networking.

Its network lacks centralized points of vulnerability that computer crackers can exploit; likewise, it has no central point of failure. Blockchain security methods include the use of public-key cryptography.[4]:5 A public key (a long, random-looking string of numbers) is an address on the blockchain. Value tokens sent across the network are recorded as belonging to that address. A private key is like a password that gives its owner access to their digital assets or the means to otherwise interact with the various capabilities that blockchains now support. Data stored on the blockchain is generally considered incorruptible.[1]

This is where blockchain has its advantage. While centralized data is more controllable, information and data manipulation are common. By decentralizing it, blockchain makes data transparent to everyone involved.[40]

Every node or miner in a decentralized system has a copy of the blockchain. Data quality is maintained by massive database replication[9] and computational trust. No centralized "official" copy exists and no user is "trusted" more than any other.[4] Transactions are broadcast to the network using software. Messages are delivered on a best effort basis. Mining nodes validate transactions,[34] add them to the block they are building, and then broadcast the completed block to other nodes.[37]:ch. 08 Blockchains use various time-stamping schemes, such as proof-of-work, to serialize changes.[41] Alternate consensus methods include proof-of-stake, proof-of-authority and proof-of-burn.[34] Growth of a decentralized blockchain is accompanied by the risk of node centralization because computer resources required to operate bigger data become more expensive.[42]

Blockchain panel discussion at the first IEEE Computer Society TechIgnite conference Journals[edit source] Main article: Ledger (journal)

Make a new request Reviewing requests If you are an experienced and autoconfirmed editor, then you can help out by reviewing requests. about c++ C++ (pronounced /ˌsiːˌplʌsˈplʌs/ "cee plus plus") is a general-purpose programming language. It has imperative, object-oriented and generic programming features, while also providing facilities for low-level memory manipulation.

It was designed with a bias toward system programming and embedded, resource-constrained and large systems, with performance, efficiency and flexibility of use as its design highlights.[7] C++ has also been found useful in many other contexts, with key strengths being software infrastructure and resource-constrained applications,[7] including desktop applications, servers (e.g. e-commerce, web search or SQL servers), and performance-critical applications (e.g. telephone switches or space probes).[8] C++ is a compiled language, with implementations of it available on many platforms. Many vendors provide C++ compilers, including the Free Software Foundation, Microsoft, Intel, and IBM.

C++ is standardized by the International Organization for Standardization (ISO), with the latest standard version ratified and published by ISO in December 2017 as ISO/IEC 14882:2017 (informally known as C++17).[9] The C++ programming language was initially standardized in 1998 as ISO/IEC 14882:1998, which was then amended by the C++03, C++11 and C++14 standards. The current C++17 standard supersedes these with new features and an enlarged standard library. Before the initial standardization in 1998, C++ was developed by Bjarne Stroustrup at Bell Labs since 1979, as an extension of the C language as he wanted an efficient and flexible language similar to C, which also provided high-level features for program organization. C++20 is the next planned standard thereafter.

Many other programming languages have been influenced by C++, including C#, D, Java, and newer versions of C.

Bjarne Stroustrup, the creator of C++ In 1979, Bjarne Stroustrup, a Danish computer scientist, began work on "C with Classes", the predecessor to C++.[10] The motivation for creating a new language originated from Stroustrup's experience in programming for his Ph.D. thesis. Stroustrup found that Simula had features that were very helpful for large software development, but the language was too slow for practical use, while BCPL was fast but too low-level to be suitable for large software development. When Stroustrup started working in AT&T Bell Labs, he had the problem of analyzing the UNIX kernel with respect to distributed computing. Remembering his Ph.D. experience, Stroustrup set out to enhance the C language with Simula-like features.[11] C was chosen because it was general-purpose, fast, portable and widely used. As well as C and Simula's influences, other languages also influenced C++, including ALGOL 68, Ada, CLU and ML.

Initially, Stroustrup's "C with Classes" added features to the C compiler, Cpre, including classes, derived classes, strong typing, inlining and default arguments.[12]

In 1983, "C with Classes" was renamed to "C++" (++ being the increment operator in C), adding new features that included virtual functions, function name and operator overloading, references, constants, type-safe free-store memory allocation (new/delete), improved type checking, and BCPL style single-line comments with two forward slashes (//). Furthermore, it included the development of a standalone compiler for C++, Cfront.

In 1985, the first edition of The C++ Programming Language was released, which became the definitive reference for the language, as there was not yet an official standard.[13] The first commercial implementation of C++ was released in October of the same year.[10]

In 1989, C++ 2.0 was released, followed by the updated second edition of The C++ Programming Language in 1991.[14] New features in 2.0 included multiple inheritance, abstract classes, static member functions, const member functions, and protected members. In 1990, The Annotated C++ Reference Manual was published. This work became the basis for the future standard. Later feature additions included templates, exceptions, namespaces, new casts, and a boolean type.

After the 2.0 update, C++ evolved relatively slowly until, in 2011, the C++11 standard was released, adding numerous new features, enlarging the standard library further, and providing more facilities to C++ programmers. After a minor C++14 update released in December 2014, various new additions were introduced in C++17, and further changes planned for 2020.[15]

As of 2017, C++ remains the third most popular programming language, behind Java and C.[16][17]

Etymology[edit source] According to Stroustrup: "the name signifies the evolutionary nature of the changes from C".[18] This name is credited to Rick Mascitti (mid-1983)[12] and was first used in December 1983. When Mascitti was questioned informally in 1992 about the naming, he indicated that it was given in a tongue-in-cheek spirit. The name comes from C's ++ operator (which increments the value of a variable) and a common naming convention of using "+" to indicate an enhanced computer program.

During C++'s development period, the language had been referred to as "new C" and "C with Classes"[12][19] before acquiring its final name.

Philosophy[edit source] Throughout C++'s life, its development and evolution has been informally governed by a set of rules that its evolution should follow:[11]

It must be driven by actual problems and its features should be useful immediately in real world programs. Every feature should be implementable (with a reasonably obvious way to do so). Programmers should be free to pick their own programming style, and that style should be fully supported by C++. Allowing a useful feature is more important than preventing every possible misuse of C++. It should provide facilities for organising programs into well-defined separate parts, and provide facilities for combining separately developed parts. No implicit violations of the type system (but allow explicit violations; that is, those explicitly requested by the programmer). User-created types need to have the same support and performance as built-in types. Unused features should not negatively impact created executables (e.g. in lower performance). There should be no language beneath C++ (except assembly language). C++ should work alongside other existing programming languages, rather than fostering its own separate and incompatible programming environment. If the programmer's intent is unknown, allow the programmer to specify it by providing manual control. Standardization[edit source] C++ is standardized by an ISO working group known as JTC1/SC22/WG21. So far, it has published five revisions of the C++ standard and is currently working on the next revision, C++20.

In 1998, the ISO working group standardized C++ for the first time as ISO/IEC 14882:1998, which is informally known as C++98. In 2003, it published a new version of the C++ standard called ISO/IEC 14882:2003, which fixed problems identified in C++98.

The next major revision of the standard was informally referred to as "C++0x", but it was not released until 2011.[24] C++11 (14882:2011) included many additions to both the core language and the standard library.[22]

In 2014, C++14 (also known as C++1y) was released as a small extension to C++11, featuring mainly bug fixes and small improvements.[25] The Draft International Standard ballot procedures completed in mid-August 2014.[26]

After C++14, a major revision C++17, informally known as C++1z, was completed by the ISO C++ Committee in mid July 2017 and was approved and published in December 2017.[27]

As part of the standardization process, ISO also publishes technical reports and specifications:

More technical specifications are in development and pending approval, including concurrency library extensions, a networking standard library, ranges, and modules.[37]

Language[edit source] The C++ language has two main components: a direct mapping of hardware features provided primarily by the C subset, and zero-overhead abstractions based on those mappings. Stroustrup describes C++ as "a light-weight abstraction programming language [designed] for building and using efficient and elegant abstractions";[7] and "offering both hardware access and abstraction is the basis of C++. Doing it efficiently is what distinguishes it from other languages".[38]

C++ inherits most of C's syntax. The following is Bjarne Stroustrup's version of the Hello world program that uses the C++ Standard Library stream facility to write a message to standard output:[39][40]

Object storage[edit source] As in C, C++ supports four types of memory management: static storage duration objects, thread storage duration objects, automatic storage duration objects, and dynamic storage duration objects.[41]

Static storage duration objects[edit source] Static storage duration objects are created before main is entered (see exceptions below) and destroyed in reverse order of creation after main exits. The exact order of creation is not specified by the standard (though there are some rules defined below) to allow implementations some freedom in how to organize their implementation. More formally, objects of this type have a lifespan that "shall last for the duration of the program".[42]

Static storage duration objects are initialized in two phases. First, "static initialization" is performed, and only after all static initialization is performed, "dynamic initialization" is performed. In static initialization, all objects are first initialized with zeros; after that, all objects that have a constant initialization phase are initialized with the constant expression (i.e. variables initialized with a literal or constexpr). Though it is not specified in the standard, the static initialization phase can be completed at compile time and saved in the data partition of the executable. Dynamic initialization involves all object initialization done via a constructor or function call (unless the function is marked with constexpr, in C++11). The dynamic initialization order is defined as the order of declaration within the compilation unit (i.e. the same file). No guarantees are provided about the order of initialization between compilation units.

Thread storage duration objects[edit source] Variables of this type are very similar to static storage duration objects. The main difference is the creation time is just prior to thread creation and destruction is done after the thread has been joined.[43]

Automatic storage duration objects[edit source] The most common variable types in C++ are local variables inside a function or block, and temporary variables.[44] The common feature about automatic variables is that they have a lifetime that is limited to the scope of the variable. They are created and potentially initialized at the point of declaration (see below for details) and destroyed in the reverse order of creation when the scope is left. This is implemented by allocation on the stack.

Local variables are created as the point of execution passes the declaration point. If the variable has a constructor or initializer this is used to define the initial state of the object. Local variables are destroyed when the local block or function that they are declared in is closed. C++ destructors for local variables are called at the end of the object lifetime, allowing a discipline for automatic resource management termed RAII, which is widely used in C++.

Member variables are created when the parent object is created. Array members are initialized from 0 to the last member of the array in order. Member variables are destroyed when the parent object is destroyed in the reverse order of creation. i.e. If the parent is an "automatic object" then it will be destroyed when it goes out of scope which triggers the destruction of all its members.

Temporary variables are created as the result of expression evaluation and are destroyed when the statement containing the expression has been fully evaluated (usually at the ; at the end of a statement).

Dynamic storage duration objects[edit source] Main article: new and delete (C++) These objects have a dynamic lifespan and are created with a call to new and destroyed explicitly with a call to delete.[45]

Templates[edit source] See also: Template metaprogramming and Generic programming C++ templates enable generic programming. C++ supports function, class, alias and variable templates. Templates may be parameterized by types, compile-time constants, and other templates. Templates are implemented by instantiation at compile-time. To instantiate a template, compilers substitute specific arguments for a template's parameters to generate a concrete function or class instance. Some substitutions are not possible; these are eliminated by an overload resolution policy described by the phrase "Substitution failure is not an error" (SFINAE). Templates are a powerful tool that can be used for generic programming, template metaprogramming, and code optimization, but this power implies a cost. Template use may increase code size, because each template instantiation produces a copy of the template code: one for each set of template arguments, however, this is the same or smaller amount of code that would be generated if the code was written by hand.[46] This is in contrast to run-time generics seen in other languages (e.g., Java) where at compile-time the type is erased and a single template body is preserved.

Templates are different from macros: while both of these compile-time language features enable conditional compilation, templates are not restricted to lexical substitution. Templates are aware of the semantics and type system of their companion language, as well as all compile-time type definitions, and can perform high-level operations including programmatic flow control based on evaluation of strictly type-checked parameters. Macros are capable of conditional control over compilation based on predetermined criteria, but cannot instantiate new types, recurse, or perform type evaluation and in effect are limited to pre-compilation text-substitution and text-inclusion/exclusion. In other words, macros can control compilation flow based on pre-defined symbols but cannot, unlike templates, independently instantiate new symbols. Templates are a tool for static polymorphism (see below) and generic programming.

In addition, templates are a compile time mechanism in C++ that is Turing-complete, meaning that any computation expressible by a computer program can be computed, in some form, by a template metaprogram prior to runtime.

In summary, a template is a compile-time parameterized function or class written without knowledge of the specific arguments used to instantiate it. After instantiation, the resulting code is equivalent to code written specifically for the passed arguments. In this manner, templates provide a way to decouple generic, broadly applicable aspects of functions and classes (encoded in templates) from specific aspects (encoded in template parameters) without sacrificing performance due to abstraction.

Objects[edit source] Main article: C++ classes C++ introduces object-oriented programming (OOP) features to C. It offers classes, which provide the four features commonly present in OOP (and some non-OOP) languages: abstraction, encapsulation, inheritance, and polymorphism. One distinguishing feature of C++ classes compared to classes in other programming languages is support for deterministic destructors, which in turn provide support for the Resource Acquisition is Initialization (RAII) concept.

Encapsulation[edit source] Encapsulation is the hiding of information to ensure that data structures and operators are used as intended and to make the usage model more obvious to the developer. C++ provides the ability to define classes and functions as its primary encapsulation mechanisms. Within a class, members can be declared as either public, protected, or private to explicitly enforce encapsulation. A public member of the class is accessible to any function. A private member is accessible only to functions that are members of that class and to functions and classes explicitly granted access permission by the class ("friends"). A protected member is accessible to members of classes that inherit from the class in addition to the class itself and any friends.

The OO principle is that all of the functions (and only the functions) that access the internal representation of a type should be encapsulated within the type definition. C++ supports this (via member functions and friend functions), but does not enforce it: the programmer can declare parts or all of the representation of a type to be public, and is allowed to make public entities that are not part of the representation of the type. Therefore, C++ supports not just OO programming, but other decomposition paradigms, like modular programming.

It is generally considered good practice to make all data private or protected, and to make public only those functions that are part of a minimal interface for users of the class. This can hide the details of data implementation, allowing the designer to later fundamentally change the implementation without changing the interface in any way.[47][48]

Inheritance[edit source] Inheritance allows one data type to acquire properties of other data types. Inheritance from a base class may be declared as public, protected, or private. This access specifier determines whether unrelated and derived classes can access the inherited public and protected members of the base class. Only public inheritance corresponds to what is usually meant by "inheritance". The other two forms are much less frequently used. If the access specifier is omitted, a "class" inherits privately, while a "struct" inherits publicly. Base classes may be declared as virtual; this is called virtual inheritance. Virtual inheritance ensures that only one instance of a base class exists in the inheritance graph, avoiding some of the ambiguity problems of multiple inheritance.

Multiple inheritance is a C++ feature not found in most other languages, allowing a class to be derived from more than one base class; this allows for more elaborate inheritance relationships. For example, a "Flying Cat" class can inherit from both "Cat" and "Flying Mammal". Some other languages, such as C# or Java, accomplish something similar (although more limited) by allowing inheritance of multiple interfaces while restricting the number of base classes to one (interfaces, unlike classes, provide only declarations of member functions, no implementation or member data). An interface as in C# and Java can be defined in C++ as a class containing only pure virtual functions, often known as an abstract base class or "ABC". The member functions of such an abstract base class are normally explicitly defined in the derived class, not inherited implicitly. C++ virtual inheritance exhibits an ambiguity resolution feature called dominance.

A database is an organized collection of data.[1] A relational database, more restrictively, is a collection of schemas, tables, queries, reports, views, and other elements. Database designers typically organize the data to model aspects of reality in a way that supports processes requiring information, such as (for example) modelling the availability of rooms in hotels in a way that supports finding a hotel with vacancies.

A database-management system (DBMS) is a computer-software application that interacts with end-users, other applications, and the database itself to capture and analyze data. A general-purpose DBMS allows the definition, creation, querying, update, and administration of databases.

A database is not generally portable across different DBMSs, but different DBMSs can interoperate by using standards such as SQL and ODBC or JDBC to allow a single application to work with more than one DBMS. Computer scientists may classify database-management systems according to the database models that they support; the most popular database systems since the 1980s have all supported the relational model - generally associated with the SQL language.[disputed – discuss] Sometimes a DBMS is loosely referred to as a "database".