note bioMan <p>Roy</p> <p>There is one difference between your algorithm and Grandfather's. His code returns the longest substring for each <b>pair</b> of input strings.</p> <p> With my original data set your code returns one substring. Grandfather's code returned over three thousand (where $minmatch = 256). On the other hand your code finds multiple occurrences of the longest common substrings, if they all have the same length, which I like.</p> <p>Mike</p> 485464 508420