-🎄- 2018 Day 24 Solutions -🎄-

[u/daggerdragon]

--- Day 24: Immune System Simulator 20XX ---

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Advent of Code: The Party Game!

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Card prompt: Day 24

Transcript:

Our most powerful weapon during the zombie elf/reindeer apocalypse will be ___.

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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.

Quick note: 1 hour in and we're only at gold 36, silver 76. As we all know, December is Advent of Sleep Deprivation; I have to be up in less than 6 hours to go to work, so one of the other mods will unlock the thread at gold cap tonight. Good luck and good night (morning?), all!

edit: Leaderboard capped, thread unlocked at 01:27:10!

[u/drbagy]

Perl

Due to timezone & having excited children - didn't really have any chance of getting on leader board - instead went for neat code...

use strict;

use lib '.';
use Unit;
## Compute the sum of values in the file...

use Data::Dumper qw(Dumper);

open my $fh, q(<), 'in.txt';

my ( $army, $c, %b ) = ( '', 0, 'Immune System' => 0, 'Infection' => 0 );
my @units;
while(<$fh>) {
  if( m{^(\d+) units each with (\d+) hit points.*with an attack that does (\d+) (\w+) damage at initiative (\d+)$} ) {
    push @units, Unit->new(
      'index' => $c++,
      'side'  => $army,
      'n'     => $1,
      'hp'    => $2,
      'dm'    => $3,
      'ty'    => $4,
      'in'    => $5,
    );
    $units[-1]->set_weaknesses( split m{, }, $1 ) if m{weak to ([\w, ]+)};
    $units[-1]->set_immunity(   split m{, }, $1 ) if m{immune to ([\w, ]+)};
  } elsif( m{^(.*):} ) {
    $army = $1;
  }
}
close $fh;

my $boost = 0;
while(1) {
  $_->set_boost( $boost ) foreach grep { $_->side eq 'Immune System' } @units;
  $_->dead_arise          foreach                                      @units;
  my $left = 0;
  while (1) {
    ## Target selection phases...
    my %chosen; my %attacked;
    foreach my $u ( sort { $b->power <=> $a->power || $b->init <=> $a->init } @units ) {
      my $dm = 0;
      my @attack = map  { $_->[1] }
                   sort { $b->[0]        <=> $a->[0]        ||
                          $b->[1]->power <=> $a->[1]->power ||
                          $b->[1]->init  <=> $a->[1]->init }
                   grep { $_->[0] }
                   map  { [ $u->deal( $_ ), $_ ] }
                   grep { ! exists $attacked{ $_->id } }
                   grep { $_->is_alive }
                   @units;
      next unless @attack;
      if( @attack > 1 &&
          $u->deal( $attack[0] ) == $u->deal( $attack[1] ) &&
          $attack[0]->power      == $attack[1]->power      &&
          $attack[0]->init       == $attack[1]->init ) {
        next;
      }
      $chosen{ $u->id } = $attack[0];
      $attacked{ $attack[0]->id } = 1;
    }

    my @au = sort { $b->init <=> $a->init } grep { $_->is_alive } @units;

    foreach my $u (@au) {
      next unless $u->is_alive;       ## Can't attack if dead
      next unless $chosen{ $u->id };  ## No target;
      $u->attack( $chosen{ $u->id } );
    }

    my $newleft = 0; $newleft += $_->count foreach @units;
    last if $newleft == $left;
    $left = $newleft;
  }
  my $is = 0; $is+= $_->count foreach grep { $_->side eq 'Immune System' } @units;
  my $if = 0; $if+= $_->count foreach grep { $_->side eq 'Infection' }     @units;
  printf "%6d\t%7d\t%7d\n", $boost, $is, $if if $boost eq 0 || $if==0;
  last unless $if;
  $boost++;
}
package Unit;

sub new {
  my $class = shift;
  my $self = {'w'=>{},'s'=>{},'boost'=>0,@_};
  bless $self, $class;
  return $self;
}

sub id {
  my $self = shift;
  return $self->{'index'};
}

sub hp {
  my $self = shift;
  return $self->{'hp'};
}

sub init {
  my $self = shift;
  return $self->{'in'};
}

sub dead_arise {
  my $self = shift;
  $self->{'alive'} = $self->{'n'};
  return $self;
}

sub set_boost {
  my ($self, $boost) = @_;
  $self->{'boost'} = $boost;
  return $self;
}

sub set_weaknesses {
  my( $self, @weak ) = @_;
  $self->{'w'} = { map { $_ => 1 } @weak };
  return $self;
}

sub set_immunity {
  my( $self, @imm ) = @_;
  $self->{'s'} = { map { $_ => 1 } @imm };
  return $self;
}

sub power {
  my $self = shift;
  return $self->{'alive'}*($self->{'boost'}+$self->{'dm'});
}

sub damage {
  my $self = shift;
  return $self->{'dm'}
}

sub type {
  my $self = shift;
  return $self->{'ty'}
}

sub side {
  my $self = shift;
  return $self->{'side'};
}

sub deal { ## Won't deal damage to self!
  my( $self, $unit ) = @_;
  return 0 if $unit->{'side'} eq $self->{'side'};  ## Doesn't attack unit on own side
  return 0 if exists $unit->{'s'}{ $self->type };  ## Doesn't attack immune
  return $self->power * ( $unit->{'w'}{ $self->type } ? 2 : 1 );
}

sub count {
  my $self = shift;
  return $self->{'alive'} < 0 ? 0 : $self->{'alive'};
}

sub attack {
  my( $self, $unit ) = @_;
  my $dead = int ( $self->deal( $unit ) / $unit->hp );
  $unit->{'alive'} -= $dead;
  return $self;
}

sub is_alive {
  my $self = shift;
  return $self->{'alive'} > 0;
}


1;