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 \(\small{x_{i+1}\leftarrow(a x_i + c)\mod m}\)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 (C++11) | 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. |
minstd_rand (C++11) | std::linear_congruential_engine<std::uint_fast32_t, 48271, 0, 2147483647>Newer "Minimum standard", recommended by Park, Miller, and Stockmeyer in 1993. |
| UIntType | - | The result type generated by the generator. The effect is undefined if this is not one of unsigned short, unsigned int, unsigned long, or unsigned long long. |
| a | - | the multiplier term |
| c | - | the increment term |
| m | - | the modulus term |
| Member type | Definition |
|---|---|
result_type (C++11) | The integral type generated by the engine. Results are undefined if this is not an unsigned integral type. |
Construction and Seeding |
|
|
(C++11) | constructs the engine (public member function) |
|
(C++11) | sets the current state of the engine (public member function) |
Generation |
|
|
(C++11) | advances the engine's state and returns the generated value (public member function) |
|
(C++11) | advances the engine's state by a specified amount (public member function) |
Characteristics |
|
|
[static] (C++11) | gets the smallest possible value in the output range (public static member function) |
|
[static] (C++11) | gets the largest possible value in the output range (public static member function) |
|
(C++11)(C++11)(removed in C++20) | compares the internal states of two pseudo-random number engines (function) |
|
(C++11) | performs stream input and output on pseudo-random number engine (function template) |
| constexpr UIntType multiplier
[static] (C++11) | the multiplier term (a). (public static member constant) |
| constexpr UIntType increment
[static] (C++11) | the increment term (c). (public static member constant) |
| constexpr UIntType modulus
[static] (C++11) | the modulus term (m). (public static member constant) |
| constexpr UIntType default_seed
[static] (C++11) | the default seed (1). (public static member constant) |
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