I haven't seen this method posted yet. It doesn't get fancy with regexps, but is fairly clear and simple to understand. Like the rest, scalability is an issue. 

use strict;
use warnings;

my @first  = qw/ short bigger longest superbig /;
my @second = qw/ short longer even longer longest /;

my $string = "";
foreach my $item ( @first ) {
    $string = $item if length $item > length $string and 
                       grep { $item eq $_ } @second;
}

print $string, "\n";

[download]

One way to improve the algorithm to scale better may be to keep the arrays ordered in decending order of length so that you could just stop searching on the first match. That would require more overhead at "insertion" time, but much less at searching time.


Dave


"If I had my life to live over again, I'd be a plumber." -- Albert Einstein

In reply to Re: finding longest common substring by davido
in thread finding longest common substring by revdiablo

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