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# std::linear_congruential_engine

From cppreference.com
< cpp‎ | numeric‎ | random

Defined in header `<random>` |  |
template< class UIntType, UIntType a, UIntType c, UIntType m > class linear_congruential_engine; |  | (since C++11)

`linear_congruential_engine` is a random number engine based on Linear congruential generator (LCG). A LCG has a state that consists of a single integer.

The transition algorithm of the LCG function is x
i+1 ← (ax
i+c) mod m.

The following typedefs define the random number engine with two commonly used parameter sets:

Defined in header `<random>`
Type | Definition
`minstd_rand0` | std::linear_congruential_engine<std::uint_fast32_t, 16807, 0, 2147483647> Discovered in 1969 by Lewis, Goodman and Miller, adopted as "Minimal standard" in 1988 by Park and Miller [edit]
`minstd_rand` | std::linear_congruential_engine<std::uint_fast32_t, 48271, 0, 2147483647> Newer "Minimum standard", recommended by Park, Miller, and Stockmeyer in 1993[edit]

### [edit] Member types

Member type | Definition
`result_type` | The integral type generated by the engine. Results are undefined if this is not an unsigned integral type.

### [edit] Member functions

##### Construction and Seeding
(constructor) | constructs the engine (public member function) [edit]
seed | sets the current state of the engine (public member function) [edit]
##### Generation
operator() | advances the engine's state and returns the generated value (public member function) [edit]
discard | advances the engine's state by a specified amount (public member function) [edit]
##### Characteristics
min [static] | gets the smallest possible value in the output range (public static member function) [edit]
max [static] | gets the largest possible value in the output range (public static member function) [edit]

### [edit] Non-member functions

operator==operator!= | compares the internal states of two pseudo-random number engines (function template) [edit]
operator<<operator>> | performs stream input and output on pseudo-random number engine (function template) [edit]

### [edit] Member objects

constexpr UIntType multiplier [static] | the multiplier term (a). (public static member constant)
constexpr UIntType increment [static] | the increment term (c). (public static member constant)
constexpr UIntType modulus [static] | the modulus term (m). (public static member constant)
constexpr UIntType default_seed [static] | the default seed (1). (public static member constant)

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