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