adventofcode/20/2.pl

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Perl
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2017-12-20 15:56:50 +00:00
use 5.20.0;
use List::AllUtils qw/ sum uniq /;
use List::UtilsBy qw/ nsort_by /;
use experimental qw/ postderef smartmatch /;
use DDP;
my $i;
my @raw = map { [ map { [ split ',' ] } /[pva]=<(.*?)>/g ] } <>;
while() {
check_collisions();
move_particles();
say scalar @raw;
}
sub move_particles {
for ( @raw ) {
for my $i ( 0..2 ) {
$_->[1][$i] += $_->[2][$i];
$_->[0][$i] += $_->[1][$i];
}
}
}
sub check_collisions {
my %seen;
my @to_delete;
for ( 0..$#raw ) {
my $k = join ':', $raw[$_][0]->@*;
push @to_delete, $seen{$k}, $_ if exists $seen{$k};
$seen{$k} = $_;
}
return unless @to_delete;
@raw = @raw[ grep { not $_ ~~ @to_delete } 0..$#raw ];
}