Python

As someone remarked today on Reddit, the entire plan hinged upon you remembering a ten digit prime number you randomly overheard twenty days ago.

Okay, this one took a long time. I knew what to do, but what to do was super slow.

We’re about to start on Christmas Week, that week when Advent of Code’s most iconic puzzles are released. But today, we’re dealing with the aftermath of an exploding volcano.

They say “Pyroclastic Flow”, but it’s really Tetris. Rock Tetris. With 100,000,000 pieces. Massive.

Trying to save elephants trapped in an erupting volcano? Sure. My solution worked for my input but not that of other people’s, so let’s try something a little different.

The title says it all. It’s a “shortest path” puzzle, you’re meant to use Dijkstra’s algorithm, and the puzzle has no curve balls to toss at you.

This is the kind of puzzle I hate. Puzzles where even the best approach seems to take forever and it’s hard to wrap my head around the solution.

I thought, for my vacation, I’d have time to really dive deep into these puzzles. Instead, I’ve been buried deep in sand – much like the hapless victim in today’s puzzle.

I thought this was just a puzzle to see if I knew about modulo arithmetic… but then it turned into a puzzle about VERY LARGE NUMBERS! Also, why do I bother with Java?

Turns out the elves just really loved the Atari 2600 so much, they built their little handheld computers around them. And now it’s up to us to fix one.