adventofcode/2023/08/Part2.pm

use 5.38.0;

package Part2;

use Part1;

use List::AllUtils qw/all /;

sub solution_2 ($input) {
    my $p          = Part1::parse_input($input);
    my @directions = $p->{directions}->@*;
    my %nodes      = $p->{nodes}->%*;

    my $visited    = 0;
    my $next_index = 0;
    my @current    = grep { /A$/ } keys %nodes;

    until ( all { /Z$/ } @current ) {
        # use DDP; p @current;
        # my $foo = <>;
        $visited++;

        @current = map {
          $nodes{$_}->[ $directions[ $next_index % @directions ] ]
      } @current;
      $next_index++;
    }

    return $visited;

}

1;

1;