in reply to Finding a LCS module on word level

I may be missing something, but isn't this kinda like (untested!): 
sub lcs {
    my ($string, $find) = @_;

    my $l = length $find;
    while ( $l > 0 ) {
        my $pos = index( $string, $find );
        if ( $pos > -1 ) {
            return ( $pos, $l );
        }

        $l--;
        chop $find;
    }

    return;
}

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My criteria for good software:
  1. Does it work?
  2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?

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Re^2: Finding a LCS module on word level
by ikegami (Patriarch) on May 09, 2008 at 02:52 UTC
    It fails for lcs('axb', 'cxd');
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      Ah, so we have to examine the powerset of substrings and not just the stem. Ok, that's just a change to the loop. I think my point still stands, though.
      My criteria for good software:
      1. Does it work?
      2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?
[reply]
        dragonchild,
        I didn't review your logic other than to see you are using index. I am fairly certain that is a flawed approach since the OP is looking for the longest common substring based on words not characters. 
        Have you ever seen the rain
I have never seen the rain

# should produce "seen the rain" not "ever seen the rain" because "eve
+r" ne "never"

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        Cheers - L~R

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