#!/usr/bin/env perl

use strict;
use warnings;
use List::Util qw(first reduce);

my @rules = ();
while (<>) {
	last if /^\s*$/;
	chomp;
	push @rules, [split /\|/];
}

my @correct_order = ();
my @incorrect_order = ();
while (<>) {
	next if /^\s*$/;
	chomp;
	my @pages = split /,/;
	
	my $hit = 1;
	for my $rule (@rules) {
		my $a = first { $pages[$_] eq $rule->[0] } 0 .. $#pages;
		my $b = first { $pages[$_] eq $rule->[1] } 0 .. $#pages;
		
		if (defined($a) && defined($b) && $a > $b) {
			$hit = 0;
			last;
		}
	}

	if ($hit) {
		push @correct_order, \@pages;
	} else {
		push @incorrect_order, \@pages;
	}
}

print "Part 1: ", reduce { $a + $b } map { $_->[@$_/2] } @correct_order; print "\n";
my @fixed_incorrect_order = map { fix_order(@$_) } @incorrect_order;
print "Part 2: ", reduce { $a + $b } map { $_->[@$_/2] } @fixed_incorrect_order; print "\n";

sub fix_order {
	my @pages = @_;

	my $rule_violated = 1;
	while ($rule_violated) {
		$rule_violated = 0;
		for my $rule (@rules) {
			my $a = first { $pages[$_] eq $rule->[0] } 0 .. $#pages;
			my $b = first { $pages[$_] eq $rule->[1] } 0 .. $#pages;
			
			if (defined($a) && defined($b) && $a > $b) {
				@pages[$a, $b] = @pages[$b, $a];
				$rule_violated = 1;
			}
		}
	}

	return \@pages;
}