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From: Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups: comp.programming
Subject: Re: Looking for simple brute force solution
Date: Thu, 04 Jan 2018 20:36:44 +0000
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root <NoEMail@home.org> writes:

> Ben Bacarisse <ben.usenet@bsb.me.uk> wrote:
>> root <NoEMail@home.org> writes:
>>
>>> Ben Bacarisse <ben.usenet@bsb.me.uk> wrote:
>>>> root <NoEMail@home.org> writes:
>>>><snip>
>>>>
>>>> You can just count up to 3^N.  Call the count i.  For each number in the
>>>> set you use i%3 to determine if you add, subtract or ignore.  For the
>>>> next number you set i = i/3 and repeat.  In effect you are pulling out
>>>> the base-3 digits of i.  (I'm using % to mean remainder and / for
>>>> integer division.)
>>>
>>> Yes, that is the solution I was looking for. Thanks.
>>>
>>> I can do that with two nested loops instead of N.
>>
>> OK, but I don't see why you need two nested loops.  That's bad news
>> because you are squaring an already exponential function.
>
> The outer loop is to count from 0 to 3^N. The inner loop is to
> work the outer loop counter down to 0 via a sequence of /3
> operations.

Ah, right, so just what I was proposing.  The wording suggested to me
that the two loops had the same bounds.

-- 
Ben.