my $num_of_rounds = 5;
while($num_of_rounds--)
{
    my %nums = ();
    for (0..24)
    {
       my $n = 0;
       while(1)
       {
          $n = int(rand(25));
          last unless exists $nums{$n};
       }
       $nums{$n} = 1;
       print "$n\t";
    }
    print "\n";
}