It's a special case and I don't think it is a problem in practice. It only happens when there is a block longer than $subStrSize (the minimum match quanta) with a repeated pattern. Test strings and results are shown below:

>string1
01010101010ddddddddddd01234566789a12345yy
>string2
0123456789b12345eeeeeeeeeeeex01010101010x
>string3
0123456789c12345ffffffffffff01010101010zz

000:001 L[  11] (   0   29)
000:002 L[  11] (   0   28)
001:002 L[  10] (   0    0)
Completed in 0.002126
Best match: >string1 - >string2. 11 characters starting at 0 and 29.
Best match: >string1 - >string3. 11 characters starting at 0 and 28.

[download]
Perl is Huffman encoded by design.

In reply to Re^2: Fast common substring matching by GrandFather
in thread Fast common substring matching by GrandFather

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