Best search algorithm to find condition within a range

Albert van der Horst albert at spenarnc.xs4all.nl
Sat Apr 18 20:08:02 CEST 2015


In article <fd544688-5e9c-418e-9ca9-11b9bcb83186 at googlegroups.com>,
 <jonas.thornvall at gmail.com> wrote:
>Den tisdag 7 april 2015 kl. 16:30:15 UTC+2 skrev Denis McMahon:
>> On Tue, 07 Apr 2015 09:29:59 -0400, Dave Angel wrote:
>>
>> > On 04/07/2015 05:44 AM, jonas.thornvall at gmail.com wrote:
>>
>> >> I want todo faster baseconversion for very big bases like base 1 000
>> >> 000, so instead of adding up digits i search it.
>>
>> > How do you know the baseconversion is the bottleneck, if you haven't
>> > written any Python code yet?
>>
>> He doesn't. He doesn't comprehend that as far as a computer is concerned
>> an integer has no specific 'base', it's only when presented in a form for
>> humans to read that it gets base information added in the representation.
>>
>> He's making these and other similar errors in the javascript groups too.
>>
>> I suspect he's one of those people that spends his time thinking up
>> elaborate solutions that he has no idea how to implement as a response to
>> dreamt up non existent problems.
>>
>> --
>> Denis McMahon, denismfmcmahon at gmail.com
>
>Bullshit declare two integers in any language one 7 and one 4 and then
>write x=7+4; if you find a programming language where that does not
>yield 11 tell me.
>
>Integers are internally assumed to be base 10 otherwise you could not
>calculate without giving the base.
>
>All operations on integers addition, subtraction, multiplication and
>division assume base 10.

Fire up a lowlevel interpreter like Forth. (e.g. gforth)

7 CONSTANT A    4 CONSTANT B
A B + PAD !

PAD now contains the sum of A and B.

Now inspect the actual computer memory:

PAD 100 DUMP

You will see the bytes, represented in base 16, but PAD
just contains 11

PAD ?

11 OK

In forth you can change the number base. That doesn't affect PAD
but the output is different

HEX
PAD ?

B OK
DECIMAL

Groetjes Albert
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert at spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst




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