#!/usr/bin/env perl
use warnings;
use strict;
use Math::Prime::Util qw/randperm/;
use List::Util qw/shuffle/;
use Algorithm::Numerical::Sample qw/sample/;
use Benchmark qw/cmpthese/;

die "Usage: $0 N K\n" unless @ARGV==2;
my ($N,$K) = @ARGV;

cmpthese(-2, {
	mpu => sub {
		my @range = randperm($N, $K);
	},
	shuf => sub {
		my @range = (shuffle 0 .. $N-1)[0 .. $K - 1];
	},
	samp => sub {
		my @range = sample (-set => [0 .. $N-1], -sample_size => $K);
	},
});
__END__

$ perl bench.pl 10 5
          Rate samp shuf  mpu
samp  326934/s   -- -86% -91%
shuf 2388541/s 631%   -- -31%
mpu  3456068/s 957%  45%   --

$ perl bench.pl 100 5
          Rate  samp  shuf   mpu
samp   76377/s    --  -86%  -98%
shuf  539280/s  606%    --  -86%
mpu  3744910/s 4803%  594%    --

$ perl bench.pl 10000 5
          Rate    samp    shuf     mpu
samp     835/s      --    -86%   -100%
shuf    5885/s    605%      --   -100%
mpu  3719610/s 445489%  63101%      --

$ perl bench.pl 100000 5000
       Rate  samp  shuf   mpu
samp 72.2/s    --  -87%  -99%
shuf  562/s  678%    --  -91%
mpu  6544/s 8958% 1064%    --