Re: Re(ALL): Putting it together

[fruiture]

I'd rather say:

my (%edgeHash,@alreadySeen);

while(<STDIN>){

    # simpler regexp
    if(/(\d+)\D+(\d+)/){
        # don't use '$a' and '$b'!
        # and don't quote "$vars"
        # in fact you can keep $1 and $2
        push @{$edgeHash{$1}}, $2 unless
              $alreadySeen[int($2)]++;
    }
}

--
http://fruiture.de

[Arien]

Well, in that case...

my (%edge, @seen);

while (<STDIN>) {
    $seen[$2]++ or push @{$edge{$1}}, $2 if /(\d+)\D+(\d+)/;
    # push @{$edge{$1}}, $2 if /(\d+)\D+(\d+)/ and not $seen[$2]++;
}

— Arien

Edit: added the commented alternative.