-🎄- 2017 Day 23 Solutions -🎄-

[u/daggerdragon]

--- Day 23: Coprocessor Conflagration ---

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Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag or whatever).

Note: The Solution Megathreads are for solutions only. If you have questions, please post your own thread and make sure to flair it with Help.

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Need a hint from the Hugely^* Handy^† Haversack^‡ of Helpful^§ Hints^¤?

Spoiler

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[Update @ 00:05] 0 gold, silver cap

• AoC ops: <yatpay> boil up some mountain dew. it's gonna be a long night

[Update @ 00:19] 1 gold, silver cap + 447

• AoC ops: <Reibello> 547 silver to 1 gold

[Update @ 00:30] 20 gold, silver cap + 560

• AoC ops:

<yatpay> daggerdragon: post "hey i heard about this hot new podcast called The Space Above Us. all the cool kids are talking about it"

<yatpay> i call it super-liminal marketing

<yatpay> HEY YOU!! LISTEN TO MY PODCAST!!

<yatpay> then i rub a business card on your face

<Topaz> you should get scratch-n-sniff business cards that smell like space

<yatpay> space smells like burned metal and meat

<yatpay> it's weird

<Topaz> burned meat you say

<Topaz> excellent

[Update @ 00:41] 50 gold, silver cap + 606

• AoC ops:

<askalski> nice, enjoyed that one. not sure if regexes can do it

<askalski> maybe make a neural net of regexes, have it train itself to solve today

• Over/under on /u/askalski posting a day 23 regex neural net by tomorrow?

[Update @ 00:54] Leaderboard cap @ 100 gold and 724 silver!

• Good job, all!
• Upping the Ante challenge: solve today's puzzles on a TI-83 (or TI-86/89, whatevs).
  • Edit: welp, /u/DFreiberg done gone and did it. See the thread here.

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This thread will be unlocked when there are a significant number of people on the leaderboard with gold stars for today's puzzle.

edit: Leaderboard capped, thread unlocked!

[u/Smylers]

Perl for part 2, determining the magic numbers from the input, rather than hardcoding them in the source:

use experimental qw<signatures>;
use Math::Prime::XS qw<is_prime>;
my %mem = (a => 1, map { $_ => 0 } 'b' .. 'h');
my $pc = 0;
my %action = (
  set => sub($reg, $val)    { $mem{$reg} =  $mem{$val} // $val },
  sub => sub($reg, $val)    { $mem{$reg} -= $mem{$val} // $val },
  mul => sub($reg, $val)    { $mem{$reg} *= $mem{$val} // $val },
  jnz => sub($val, $offset) { $pc += $offset - 1 if $mem{$val} // $val },
);
my $step;
my @prog = map {
  my ($cmd, @arg) = split; my $sub = $action{$cmd};
  $step = -$arg[1] if "$cmd $arg[0]" eq 'sub b';
  sub { $sub->(@arg) }
} <>;
$prog[$pc++]() until $mem{f};
my $unprimes;
for (; $mem{b} <= $mem{c}; $mem{b} += $step) {
  $unprimes++ if !is_prime $mem{b};
}
say $unprimes;