my @pop = (1..100);
my $samples = 30;
my @sample = rand_samp(30,@pop);
print "@sample";
 
sub rand_samp {
   my ($n,@n) = (shift,@_);
   return 0 unless ($n < scalar @n);# see note below  
   my %seen = ();
   until (keys %seen == $samples) {
      $seen{$pop[rand @pop]}=1;
   }    
   return(keys %seen);
}