here is quick solution. See if it is useful for you.

sub split_array
{
my @not_sorted = qw(Ape Arg Beep Circus);
my @sorted = sort {$a cmp $b} @not_sorted;
my @A = ();
my @trash = ();

map{$_ =~/^A.*/ ? push(@A,$_):push(@trash,$_)} @sorted;

print "\n",@A,"\n";
print "\n",@trash,"\n";

}
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