====== Chess - Programming - PRNG (Pseudo Random Number Generator) ======

**Pseudo Random Number Generator(PRNG)** refers to an algorithm that uses mathematical formulas to produce sequences of random numbers.

  * PRNGs generate a sequence of numbers approximating the properties of random numbers.
  * It is not possible to generate truly random numbers from deterministic thing like computers so PRNG is a technique developed to generate random numbers using a computer.

A PRNG starts from an arbitrary starting state using a seed state.

  * Many numbers are generated in a short time and can also be reproduced later, if the starting point in the sequence is known.
  * Hence, the numbers are deterministic and efficient.

Widely used PRNG algorithms include: Lagged Fibonacci generators, linear feedback shift registers, Blum Blum Shub. 

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===== Characteristics of PRNG =====

  * Efficient: 
    * PRNG can produce many numbers in a short time and is advantageous for applications that need many numbers.
  * Deterministic: 
    * A given sequence of numbers can be reproduced at a later date if the starting point in the sequence is known.
    * Determinism is handy if you need to replay the same sequence of numbers again at a later stage.
  * Periodic:
    * PRNGs are periodic, which means that the sequence will eventually repeat itself.
    * While periodicity is hardly ever a desirable characteristic, modern PRNGs have a period that is so long that it can be ignored for most practical purposes

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===== Applications of PRNG =====

PRNGs are suitable for applications where many random numbers are required and where it is useful that the same sequence can be replayed easily.

  * Popular examples of such applications are simulation and modeling applications.
  * PRNGs are not suitable for applications where it is important that the numbers are really unpredictable, such as data encryption and gambling.

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[[Chess:Programming:PRNG (Pseudo Random Number Generator):A Pseudo Random Number Generator using srand()|A Pseudo Random Number Generator using srand()]]

[[Chess:Programming:PRNG (Pseudo Random Number Generator):Linear Congruential Generator|Linear Congruential Generator]]



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===== References =====

https://en.wikipedia.org/wiki/Linear_congruential_generator

https://www.pcg-random.org/index.html