From: Ben Bacarisse <ben.usenet@bsb.me.uk>
Subject: Re: project euler 29
Date: Mon, 18 Sep 2023 01:16:19 +0100 [thread overview]
Message-ID: <8734zcl4j0.fsf@bsb.me.uk> (raw)
In-Reply-To: 87zg1kpcjh.fsf@nightsong.com
Paul Rubin <no.email@nospam.invalid> writes:
> Ben Bacarisse <ben.usenet@bsb.me.uk> writes:
>>> Also, do you have a different approach to solve this 29th problem?
>>
>> Yes, but it's not in Ada. I implemented an equality test for a^b ==
>> c^d.
>
> Oh interesting, based on a comment in Francesc's code, I think I see a
> method to do it without the auxiliary array, at a small increase in
> runtime cost. Basically given a and b, you can find their prime factors
> and easily enumerate the combinations x,y with a**b==x**y and
> 1 <= x,y <= 100. You can label each "equivalence class" by the (a,b)
> with the smallest possible a.
>
> So you just loop through 1 <= a,b <= 100 and count only the a,b pairs
> where a is the smallest a for its equivalence class. I might see if I
> can code this, which should also let me describe it more concisely.
This is likely to be fast which is why I wanted to compile Francesc's to
try it out. Mind you, a naive a^b == c^d test gives pretty good
performance for the kind of range requested.
--
Ben.

next prev parent reply other threads:[~2023-09-18 0:16 UTC|newest]
**Thread overview: **23+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-15 9:03 project euler 29 CSYH (QAQ)
2023-09-15 9:50 ` Jeffrey R.Carter
2023-09-15 18:04 ` Keith Thompson
2023-09-15 15:42 ` Ben Bacarisse
2023-09-16 10:07 ` Francesc Rocher
2023-09-16 20:59 ` Ben Bacarisse
2023-09-16 21:56 ` Ben Bacarisse
2023-09-17 18:56 ` Francesc Rocher
2023-09-17 22:54 ` Paul Rubin
2023-09-17 23:08 ` Ben Bacarisse
2023-09-18 0:09 ` Paul Rubin
**2023-09-18 0:16 ` Ben Bacarisse [this message]**
2023-09-18 5:16 ` Paul Rubin
2023-09-18 11:31 ` Ben Bacarisse
2023-09-18 13:04 ` Francesc Rocher
2023-09-18 14:20 ` Ben Bacarisse
2023-09-18 16:55 ` Francesc Rocher
2023-09-18 19:22 ` Ben Bacarisse
2023-09-18 19:38 ` Paul Rubin
2023-09-18 19:52 ` comp.lang.ada
2023-09-18 19:56 ` comp.lang.ada
2023-09-18 20:01 ` Ben Bacarisse
2023-09-15 16:34 ` Jeffrey R.Carter

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