hkey => sub{
		my @range = (keys %{+{map {($_ => 1)}0 .. $N-1}})[0 .. $K-1];
   }


##</code><code>##

perl randomshuffle.pl 10 5
          Rate  samp  hkey  shuf   mpu
samp  108393/s    --  -13%  -88%  -92%
hkey  124178/s   15%    --  -87%  -90%
shuf  934174/s  762%  652%    --  -27%
mpu  1275273/s 1077%  927%   37%    --


##</code><code>##

 
perl randomshuffle.pl 100 5
          Rate  hkey  samp  shuf   mpu
hkey   15844/s    --  -46%  -93%  -99%
samp   29546/s   86%    --  -86%  -98%
shuf  212991/s 1244%  621%    --  -86%
mpu  1519656/s 9491% 5043%  613%    --