RosettaCodeData/Task/Pseudo-random-numbers-Splitmix64/Perl/pseudo-random-numbers-splitmix64.pl
2023-07-01 13:44:08 -04:00

36 lines
940 B
Perl

use strict;
use warnings;
no warnings 'portable';
use feature 'say';
use Math::AnyNum qw(:overload);
package splitmix64 {
sub new {
my ($class, %opt) = @_;
bless {state => $opt{seed}}, $class;
}
sub next_int {
my ($self) = @_;
my $next = $self->{state} = ($self->{state} + 0x9e3779b97f4a7c15) & (2**64 - 1);
$next = ($next ^ ($next >> 30)) * 0xbf58476d1ce4e5b9 & (2**64 - 1);
$next = ($next ^ ($next >> 27)) * 0x94d049bb133111eb & (2**64 - 1);
($next ^ ($next >> 31)) & (2**64 - 1);
}
sub next_float {
my ($self) = @_;
$self->next_int / 2**64;
}
}
say 'Seed: 1234567, first 5 values:';
my $rng = splitmix64->new(seed => 1234567);
say $rng->next_int for 1 .. 5;
my %h;
say "\nSeed: 987654321, values histogram:";
$rng = splitmix64->new(seed => 987654321);
$h{int 5 * $rng->next_float}++ for 1 .. 100_000;
say "$_ $h{$_}" for sort keys %h;