From owner-freebsd-hackers  Wed Feb 25 14:29:12 1998
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Date: Thu, 26 Feb 1998 00:28:46 +0200
From: Anatoly Vorobey <mellon@pobox.com>
To: hackers@FreeBSD.ORG
Subject: Re: RE: New utilities: factor(1) and wid(1)?
References: <01BD420C.2FCDD020.meuston@jmrodgers.com>
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In-Reply-To: <01BD420C.2FCDD020.meuston@jmrodgers.com>; from Max Euston on Wed, Feb 25, 1998 at 04:41:11PM -0500
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You, Max Euston, were spotted writing this on Wed, Feb 25, 1998 at 04:41:11PM -0500:

> when I should have tried:
> 
> 	$ man factor
> 
> Didn't expect to find it in 'games' ??? - That is not in my PATH=.

That's history for you, I guess.

> It uses the 'primes' utility and is doing division (on 'long's) - I will do 
> some investigating to see if it is faster than my method and see if it will 
> scale to 'long long's.

It won't, at least not easily. It keeps a fixed precomputed table
of all primes up to 2^16 to do a simple sieve (in 
/usr/src/games/primes/pr_tbl.c, also used by primes(1)); would be, 
err, an interesting exercize to change that to a fixed precomputed 
table of all primes up to 2^32 and watch the executable size go up,
up, up into tens of megabytes and beyond...

It's time for to rewrite them both to use a more modern method 
of factoring, I guess. It's been some 2500 years or so; ole' good 
Eratosthenes could use some rest :)

Have a good one,
Anatoly.

P.S. What's the "politically correct" way to specify a long long
in FreeBSD: 'long long'? 'int64_t'? 'quad_t'?

-- 
Anatoly Vorobey,
mellon@pobox.com http://pobox.com/~mellon/
"Angels can fly because they take themselves lightly" - G.K.Chesterton

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