[FWP] words words words

[Steven Alexander <stevena@teleport.com>]

What would be a fun (short | elegant | fast) way, given two files
with nine- and three-letter words one per line, respectively, of
listing only those nines which are the concatenation of three
threes?

Anyone who wants to go so far as to do relative benchmarks
should use the three- and nine-letter words from
<http://www.geocities.com/TimesSquare/Castle/5057/TWL98.zip>

Here's the shortest I have (modulo whitespace):

#!/usr/local/bin/perl -nw
BEGIN {
    open T, "threes";
    chomp (@t = <T>);
    $re = join '|', @t;
}
/^(?:$re)*$/o && print;

and this is my fastest:

#!/usr/local/bin/perl -w
open T, "threes"; chomp(@t = <T>);
undef $/;
open N, "nines" ;       $n = <N>;
for(@t) {
    $n =~ s/$_(?=(?:...)*\n)/\L$_/g;
}
$n =~ s/^[a-z]*[A-Z][A-Za-z]+\n//gm;
print $n;


  Steven Alexander
  stevena@teleport.com
  <http://www.teleport.com/~stevena/>

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