< cpp‎ | numeric‎ | random
Pseudo-random number generation
Uniform random bit generators
Engines and engine adaptors
Non-deterministic generator
Uniform distributions
Bernoulli distributions
Poisson distributions
Normal distributions
Sampling distributions
Seed Sequences
C library
Defined in header <random>

    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
← (ax
+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[edit]

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[edit]


[edit] Template parameters

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

[edit] Member types

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.

[edit] Member functions

Construction and Seeding
constructs the engine
(public member function) [edit]
sets the current state of the engine
(public member function) [edit]
advances the engine's state and returns the generated value
(public member function) [edit]
advances the engine's state by a specified amount
(public member function) [edit]
[static] (C++11)
gets the smallest possible value in the output range
(public static member function) [edit]
[static] (C++11)
gets the largest possible value in the output range
(public static member function) [edit]

[edit] Non-member functions

(C++11)(C++11)(removed in C++20)
compares the internal states of two pseudo-random number engines
(function) [edit]
performs stream input and output on pseudo-random number engine
(function template) [edit]

[edit] Member constants

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)

[edit] Example