Day 1: Historian Hysteria
Megathread guidelines
- Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)
- You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://blocks.programming.dev if you prefer sending it through a URL
FAQ
- What is this?: Here is a post with a large amount of details: https://programming.dev/post/22323136
- Where do I participate?: https://adventofcode.com/
- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465
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2 points
*
Raku
I’m trying warm up to Raku again.
Solution
use v6;
sub MAIN($input) {
my $file = open $input;
grammar LocationList {
token TOP { <row>+%"\n" "\n"* }
token row { <left=.id> " "+ <right=.id> }
token id { \d+ }
}
my $locations = LocationList.parse($file.slurp);
my @rows = $locations<row>.map({ (.<left>.Int, .<right>.Int)});
my $part-one-solution = (@rows[*;0].sort Z- @rows[*;1].sort)».abs.sum;
say "part 1: $part-one-solution";
my $rbag = bag(@rows[*;1].sort);
my $part-two-solution = @rows[*;0].map({ $_ * $rbag{$_}}).sum;
say "part 2: $part-two-solution";
}
I’m happy to see that Lemmy no longer eats Raku code.