in reply to
Rewrite Program Using Arrays
Pushing data around from one array to the other is very unlikely to make things faster, probably the opposite. One thing you could so is write foreach my $word (split $line) to avoid the extra array, but this is something I suspect the Perl compiler might optimize all by itself already, you have top try whether it makes a difference. hashDescend() as a simple code block would probably be slightly faster, but other than that there's little room for optimization as far as I can see. Is this really too slow for your job?