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

  • @voleEnglish
    2•2 days ago

    Raku

    I’m trying warm up to Raku again.

    Solution

    github

    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.