day19.pl

#!/usr/bin/env perl

use strict;
use warnings;

use File::Slurp qw/read_file/;
use Algorithm::Combinatorics qw/permutations combinations/;
use List::Util qw/max/;
use Data::Dumper;

chomp(my @input = read_file('input'));
my ($a, $b) = (0,0);

my $grid = [[]];
my $i = 0;
foreach my $line (@input) {
	$grid->[$i++] = [split //, $line];
}

my ($x, $y) = (0,157);
my $cur = $grid->[$x][$y];
my @dir = (1,0);
my $steps = 1;

sub nxt {
	if ($grid->[$x+$dir[0]][$y+$dir[1]] ne ' ') {
		return ($x+$dir[0], $y+$dir[1]);
	}

	my @left = ($dir[1], $dir[0]);
	my @right = (-1*$dir[1], -1*$dir[0]);

	if ($grid->[$x+$left[0]][$y+$left[1]] ne ' ') {
		@dir = @left;
		return ($x+$left[0], $y+$left[1]);
	}

	if ($grid->[$x+$right[0]][$y+$right[1]] ne ' ') {
		@dir = @right;
		return ($x+$right[0], $y+$right[1]);
	}

	return ();
}

my @seen = ();

while (($x, $y) = nxt()) {
	$cur = $grid->[$x][$y];
	push @seen, $cur if $cur =~ m/[a-z]/i;
	$steps++;
}

$a = join '', @seen;
$b = $steps;

print "Part One Result: $a\n";
print "Part Two Result: $b\n";