adventofcode/2017/11/1.pl

51 lines
770 B
Perl

use 5.20.0;
my $path = <>;
chomp $path;
my %path;
$path{$_}++ for split ',', $path;
use DDP;
my %d = (
n => [ 0,1],
s => [ 0,-1],
e => [ 1, 0],
w => [ -1,0],
);
use experimental 'postderef', 'signatures';
for my $y ( qw/ n s / ){
for my $e ( qw/ e w / ){
$d{"$y$e"} = [ map { $_/2 } add( $d{$y}, $d{$e} )->@* ];
}
}
my $position = [0,0];
use List::AllUtils qw/ reduce min /;
$position = reduce { add($a,$d{$b}) } $position, split ',', $path;
p %d;
p %path;
p $position;
my @position = map { abs } @$position;
my $to_go = 0;
my $i = min @position;
$to_go = 2 * $i;
@position = map { $_ - $i } @position;
$to_go += 2 * $position[0] + $position[1];
say $to_go;
sub add($x,$y) {
[ map { $x->[$_] + $y->[$_] } 0..1 ]
}