Anonymous user
Linear congruential generator: Difference between revisions
→{{header|rust}}: add rust
(<lang julia></lang>) |
(→{{header|rust}}: add rust) |
||
Line 2,479:
9 794471793 10450
10 551188310 30612</pre>
=={{header|Rust}}==
<lang rust>extern crate rand;
pub use rand::{Rng, SeedableRng};
pub struct BsdLcg {
state: u32,
}
impl Rng for BsdLcg {
// Because the output is in the range [0, 2147483647], this should technically be `next_u16`
// (the largest integer size which is fully covered, as `rand::Rng` assumes). The `rand`
// crate does not provide it however. If serious usage is required, implementing this
// function as a concatenation of two `next_u16`s (elsewhere defined) should work.
fn next_u32(&mut self) -> u32 {
self.state = self.state.wrapping_mul(1_103_515_245).wrapping_add(12_345);
self.state %= 1 << 31;
self.state
}
}
impl SeedableRng<u32> for BsdLcg {
fn from_seed(seed: u32) -> Self {
Self { state: seed }
}
fn reseed(&mut self, seed: u32) {
self.state = seed;
}
}
pub struct MsLcg {
state: u32,
}
impl Rng for MsLcg {
// Similarly, this outputs in the range [0, 32767] and should output a `u8`. Concatenate
// four `next_u8`s for serious usage.
fn next_u32(&mut self) -> u32 {
self.state = self.state.wrapping_mul(214_013).wrapping_add(2_531_011);
self.state %= 1 << 31;
self.state >> 16 // rand_n = state_n / 2^16
}
}
impl SeedableRng<u32> for MsLcg {
fn from_seed(seed: u32) -> Self {
Self { state: seed }
}
fn reseed(&mut self, seed: u32) {
self.state = seed;
}
}
fn main() {
println!("~~~ BSD ~~~");
let mut bsd = BsdLcg::from_seed(0);
for _ in 0..10 {
println!("{}", bsd.next_u32());
}
println!("~~~ MS ~~~");
let mut ms = MsLcg::from_seed(0);
for _ in 0..10 {
println!("{}", ms.next_u32());
}
// Because we have implemented the `rand::Rng` trait, we can generate a variety of other types.
println!("~~~ Others ~~~");
println!("{:?}", ms.gen::<[u32; 5]>());
println!("{}", ms.gen::<bool>());
println!("{}", ms.gen_ascii_chars().take(15).collect::<String>());
}</lang>
=={{header|Scala}}==
| |||