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| References | <CALyJZZVU+j64Jn7fqqzLmwW+KcM=43UMKjo=HW7umnq8MSP2Uw@mail.gmail.com> <lbrjjq$96p$1@ger.gmane.org> <lbrlel$vpq$1@ger.gmane.org> |
|---|---|
| From | Vincent Davis <vincent@vincentdavis.net> |
| Date | 2014-01-23 13:50 -0600 |
| Subject | Re: generate De Bruijn sequence memory and string vs lists |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.5905.1390506641.18130.python-list@python.org> (permalink) |
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On Thu, Jan 23, 2014 at 12:02 PM, Peter Otten <__peter__@web.de> wrote: > > I just noted that the first Python loop can be eliminated: > > def debruijn(k, n): > a = k * n * bytearray([0]) > sequence = bytearray() > extend = sequence.extend # factor out method lookup > def db(t, p): > if t > n: > if n % p == 0: > extend(a[1: p+1]) > else: > a[t] = a[t - p] > db(t + 1, p) > for j in xrange(a[t - p] + 1, k): > a[t] = j > db(t + 1, t) > db(1, 1) > return sequence.translate(_mapping) I am not really sure what _mapping should be. The code above does not run because NameError: global name '_mapping' is not defined I tried to get the bytearray sequence to convert to ascii but don't know how to. Vincent Davis
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Re: generate De Bruijn sequence memory and string vs lists Vincent Davis <vincent@vincentdavis.net> - 2014-01-23 13:50 -0600
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