adventofcode/2022/05/Part1.pm
2022-12-07 18:42:05 -05:00

57 lines
1.1 KiB
Perl

package Part1;
use 5.36.0;
our @ISA = 'Exporter';
our @EXPORT_OK = qw/ part1 $sample /;
use Path::Tiny;
our $sample = path('./sample')->slurp;
sub parse_heaps($heaps) {
my( $header, @crates ) = reverse split "\n", $heaps;
my @stacks;
while( $header !~ /^\s*$/ ) {
$header =~ s/^(\s+)\d//;
my $n = length $1;
@crates = map { no warnings; substr $_, $n } @crates;
my @stack = grep { /\w/ } map { no warnings; s/(.)//; $1 } @crates;
push @stacks, \@stack;
}
return @stacks;
}
sub parse_commands($text) {
return map { [/\d+/g] } split "\n", $text
}
sub move_stacks($stacks, $commands) {
for my $command ( @$commands ) {
for( 1..$command->[0] ) {
push $stacks->[$command->[2] - 1]->@*,
pop $stacks->[$command->[1]- 1]->@*;
}
}
return @$stacks;
}
sub part1($text) {
my( $heaps, $commands ) = split "\n\n", $text;
my @heaps = parse_heaps($heaps);
my @commands = parse_commands($commands);
my @stacks = move_stacks( \@heaps, \@commands );
return join '', map { pop @$_ } @stacks;
}
1;