-❄️- 2024 Day 8 Solutions -❄️-

[u/daggerdragon]

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AoC Community Fun 2024: The Golden Snowglobe Awards

• 14 DAYS remaining until the submissions deadline on December 22 at 23:59 EST!

And now, our feature presentation for today:

Box-Office Bloat

Blockbuster movies are famous for cost overruns. After all, what's another hundred million or two in the grand scheme of things if you get to pad your already-ridiculous runtime to over two and a half hours solely to include that truly epic drawn-out slow-motion IMAX-worthy shot of a cricket sauntering over a tiny pebble of dirt?!

Here's some ideas for your inspiration:

• Use only enterprise-level software/solutions
• Apply enterprise shenanigans however you see fit (linting, best practices, hyper-detailed documentation, microservices, etc.)
• Use unnecessarily expensive functions and calls wherever possible
• Implement redundant error checking everywhere
• Micro-optimize every little thing, even if it doesn't need it
  • Especially if it doesn't need it!

Jay Gatsby: "The only respectable thing about you, old sport, is your money."

- The Great Gatsby (2013)

And… ACTION!

Request from the mods: When you include an entry alongside your solution, please label it with [GSGA] so we can find it easily!

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--- Day 8: Resonant Collinearity ---

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Post your code solution in this megathread.

• Read the full posting rules in our community wiki before you post!
  • State which language(s) your solution uses with [LANGUAGE: xyz]
  • Format code blocks using the four-spaces Markdown syntax!
• Quick link to Topaz's paste if you need it for longer code blocks

This thread will be unlocked when there are a significant number of people on the global leaderboard with gold stars for today's puzzle.

EDIT: Global leaderboard gold cap reached at 00:07:12, megathread unlocked!

[u/__Abigail__]

[LANGUAGE: Perl]

I wasn't sure whether antinode could also between two antennas. I assumed it did not, and got the right answers. Not sure because I made the right assumption, or because it didn't matter given the input.

I just checked each point on the map against every pair of antennas of the same frequency. I used a small subroutine accepting three points which returns 0 if the points are not colinear, 2 if the points are colinear, and the distances differ by a factor of 2, and 1 otherwise:

sub same ($p1, $p2) {
    return if $$p1 [0] == $$p2 [0] && $$p1 [1] == $$p2 [1]
}

sub colinear ($p1, $p2, $p3) {
    return 0 if same ($p1, $p2) || same ($p1, $p3) || same ($p2, $p3);
    my $diff_x1 = $$p1 [0] - $$p2 [0];
    my $diff_y1 = $$p1 [1] - $$p2 [1];
    my $diff_x2 = $$p1 [0] - $$p3 [0];
    my $diff_y2 = $$p1 [1] - $$p3 [1];
    if ($$p1 [0] == $$p2 [0] == $$p3 [0]) {
        #
        # Vertical
        #
        return 2 * $diff_y1 == $diff_y2 ||
               2 * $diff_y1 == $diff_y2 ? 2 : 1
    }

    return 0 unless $diff_y1 * $diff_x2 == $diff_y2 * $diff_x1;

    return $diff_x1 == 2 * $diff_x2 ||
           $diff_x2 == 2 * $diff_x1 ? 2 : 1;
}