One of the rules of PerlMonks is not to do homework, so you won't get a reply to this question. The same applies to questions amounting to "please do my work for me".

However, you may get some help if you post the code you already have and point out specific questions about that.

At any rate, you'll find the Tutorials on this site helpful.

Just my 2 cents, -gjb-

I did not notice the words "as I'm sure my teacher would iterate" in the original post, and have therefore removed my complete ready-to-use answer. Damn, a question I answered correctly too :)

As a replacement, I offer some advice. Don't ask others to do your homework. Ask for pointers as to where to look the information up and do the work yourself. I'll pretend that's what you asked of us and give you the pointers:

• split will allow you to split a string using a pattern or character(s). Your example will make good use of a line such as split('', $string);. The '' splits a string on every character.
• join is split's evil twin. Your example might want to use join('', $sorted_letters);.
• sort: Guess what? You do want to use Perl's sorting functions. They make life easy. Specifically, learn the difference between <=> and cmp for comparing. Also, you'll want to use either lc or uc to sort alphabetically instead of by ASCII value.
• my $line = <STDIN>; will get a line of text (ending in a newline "\n") from the command line.
• chomp: Will remove the newline from a line of text. Using it to remove the newline from <STDIN> will be useful.

Anyway, here is a solution. I'm not going to say which one it is, I suggest you look into it yourself If you are tempted to hand this in to your teacher.

my $text="qwertyuiopasdfghjklzxcvbnm";

my @ltrs=split //,$text;

my ($val,@set,@unset)=(1);

while ($val) {
    push @{(ord($_) & $val) ? \@set : \@unset}, $_
        foreach @ltrs;
    $val <<= 1;
    @ltrs=( splice( @unset, 0, @unset ), splice( @set, 0, @set ) );
}

print join("-",@ltrs)."\n"
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--- demerphq
my friends call me, usually because I'm late....

I'm brand spankin' new to Perl and am still having trouble picking up the syntax necessary to execute some basic data movement structures.