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Groups > comp.lang.python > #64668

Re: generate De Bruijn sequence memory and string vs lists

From Gregory Ewing <greg.ewing@canterbury.ac.nz>
Newsgroups comp.lang.python
Subject Re: generate De Bruijn sequence memory and string vs lists
Date 2014-01-24 21:29 +1300
Message-ID <bkemj0F48q8U1@mid.individual.net> (permalink)
References <CALyJZZVU+j64Jn7fqqzLmwW+KcM=43UMKjo=HW7umnq8MSP2Uw@mail.gmail.com> <lbrf82$fb3$1@ger.gmane.org> <mailman.5903.1390500573.18130.python-list@python.org>

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Vincent Davis wrote:
> I plan to use the sequence as an index to count occurrences of sequences 
> of length n.

If all you want is a mapping between a sequence of
length n and compact representation of it, there's
a much simpler way: just convert it to a base-k
integer, where k is the size of the alphabet.

The resulting integer won't be any larger than an
index into the de Bruijn sequence would be, and
you can easily recover the original sequence from
its encoding without needing any kind of lookup
table.

-- 
Greg

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Thread

Re: generate De Bruijn sequence memory and string vs lists Vincent Davis <vincent@vincentdavis.net> - 2014-01-23 11:10 -0600
  Re: generate De Bruijn sequence memory and string vs lists Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-01-24 21:29 +1300
    Re: generate De Bruijn sequence memory and string vs lists Vincent Davis <vincent@vincentdavis.net> - 2014-01-24 07:20 -0600
    Re: generate De Bruijn sequence memory and string vs lists Greg Ewing <greg.ewing@canterbury.ac.nz> - 2014-01-25 18:11 +1300

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