Space/Time tradeoff (was: Re: Video games are a waste of life)

On Sun, 20 Jul 2025 20:21:17 -0500, "Lane \"Stonehowler\" Waldby"
<wichitajayhawks@msn.com> wrote in <me5j0dFmse5U2@mid.individual.net>:

vallor wrote:

On Tue, 20 Jun 2023 18:35:04 -0700 (PDT), entwickeln14 wrote:
 

On Saturday, June 17, 2023 at 8:07:31 PM UTC-4, nikolai kingsley
wrote:

"a while ago" being around 1988.

>
Hello.
What's new?
>
e

 
hi
 
In 8th grade, I wrote a game on the Commodore PET.  You would maneuver
your avatar (an asterisk) through a landscape of constantly-changing
random blocks appearing and disappearing.
 
Kind of a funky maze game.  Would have been around 1981.
 

Lies.  You never did that. You can't even count to 1981.

Not only did I write it, I optimized the movement keys by using the
numeric keypad numbers as indices for two arrays that held +/-1 values
for x and y.

Was a lot faster than the "if then" chain I was using previously.

(This was in PET BASIC, of course.)

Recently I asked ChatGPT about the principle I'd used, and it
called it "time for space trade off".  Posted about it in
comp.theory in passing.

Message-ID: <101bvbm$58on$2@dont-email.me>

It's pretty obvious that pre-computing values can speed
things up.  Orthogonally-related, I once made a lookup
table for IPv4 unicast addresses whose decimal representation
was an md5 hash.

-rw-rw-r-- 1 xxx xxx  75161927360 May  6  2016 md5_ipv4_rainbow.b

(Turns out, back in the days of Usenet yore, certain NSP's didn't
salt their posting-host hashes.  Used it to figure out who was
posting as certain socks in a.u.k.)

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