in reply to Creating Dictionaries

The bottleneck in your program seems the sorting at the end. Sorting is super-linear, which means that if your input size doubles, the running time more than doubles.

I'd write your program slightly different, but that shouldn't make much of a difference:

my (%hash, $line); while ($line = <STDIN>) { while (my ($word) = (lc $word) =~ /[a-z]{2,}/g) { next if $word =~ /(.)\1\1\1\1/; $hash{$word}++; } } print "$_\n" for sort keys %hash;
Now, if the words are in order, there's no need for the hash, or the sorting:
my ($line, $prev); $prev = ""; while ($line = <STDIN>) { while (my ($word) = (lc $word) =~ /[a-z]{2,}/g) { next if $word =~ /(.)\1\1\1\1/; next if $word eq $prev; print "$word\n"; $prev = $word; } }
(Code fragments are untested)
Perl --((8:>*