A day of coding

The ancient civilization on Pluto was known for its ability to manipulate spacetime, and while The Historians explore their infinite corridors, you’ve noticed a strange set of physics-defying stones.

-- Day 11 - Advent of Code 2024

Solution in Java

Full source can be found: in GitHub

Part 1

For today the first step is writing a recursive method that computes the amount of blinks per stone in the input. This method stonesAfterBlink accepts the amount of blinks remaining, which is 25 for part 1. And uses a map as a cache, to prevent recalculation of any situation with the same amount of blinks left and for the same stone.

You all arrive at a Lava Production Facility on a floating island in the sky. As the others begin to search the massive industrial complex, you feel a small nose boop your leg and look down to discover a reindeer wearing a hard hat.

-- Day 10 - Advent of Code 2024

Solution in Java

Full source can be found: in GitHub

Part 1

The first step of today is to write a path finding algorithm based on Dijkstra. This will look for any path where each step size would be exactly 1 (line 12). And if the number 9 is found then the amount of found paths is increased.

Another push of the button leaves you in the familiar hallways of some friendly amphipods! Good thing you each somehow got your own personal mini submarine. The Historians jet away in search of the Chief, mostly by driving directly into walls.

-- [Day 9 - Advent of Code 2024[(https://adventofcode.com/2024/day/9)

Solution in Java

Full source can be found: in GitHub

Since todays challenge talks about disk usage with two potential states, one containing files (the FileSegment) the other being empty (the Spacing), I decided to model that out first.

You find yourselves on the roof of a top-secret Easter Bunny installation.

While The Historians do their thing, you take a look at the familiar huge antenna. Much to your surprise, it seems to have been reconfigured to emit a signal that makes people 0.1% more likely to buy Easter Bunny brand Imitation Mediocre Chocolate as a Christmas gift! Unthinkable!

-- Day 8 - Advent of Code 2024

Solution in Java

Full source can be found: in GitHub

Day 7 assignment

The Historians take you to a familiar rope bridge over a river in the middle of a jungle. The Chief isn’t on this side of the bridge, though; maybe he’s on the other side?

-- Day 7 - Advent of Code 2024

Solution in Java

Full source can be found: in GitHub

For today I setup a small little interface Instruction to capture the instructions that we can apply on the input numbers. As well as already adding the LiteralValue implementation of this interface to capture numbers. This would help to compute the possible answers in the two parts of today.

Day 6 assignment

The Historians use their fancy device again, this time to whisk you all away to the North Pole prototype suit manufacturing lab… in the year 1518! It turns out that having direct access to history is very convenient for a group of historians.

You still have to be careful of time paradoxes, and so it will be important to avoid anyone from 1518 while The Historians search for the Chief. Unfortunately, a single guard is patrolling this part of the lab.

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Day 5 assignment

Satisfied with their search on Ceres, the squadron of scholars suggests subsequently scanning the stationery stacks of sub-basement 17.

The North Pole printing department is busier than ever this close to Christmas, and while The Historians continue their search of this historically significant facility, an Elf operating a very familiar printer beckons you over.

-- Day 5 - Advent of Code 2024

Solution in Java

Full source can be found: in GitHub

Day 4 assignment

“Looks like the Chief’s not here. Next!” One of The Historians pulls out a device and pushes the only button on it. After a brief flash, you recognize the interior of the Ceres monitoring station!

-- Day 3 - Advent of Code 2024

Solution in Java

Full source can be found: in GitHub

Part 1

For the first part of today I chose to re-use my CharGrid class. With this I can iterate of all of the columns and rows looking for the X in any spot.

Day 3 assignment

“Our computers are having issues, so I have no idea if we have any Chief Historians in stock! You’re welcome to check the warehouse, though,” says the mildly flustered shopkeeper at the North Pole Toboggan Rental Shop. The Historians head out to take a look.

Day 3 - Advent of Code 2024

Solution in Java

Full source can be found: in GitHub

Part 1

For part 1 I decided to use a regular expression (line 4) to extract all the mul(x,y) instructions of the input. For each match we find the result is converted to a number using a multiplication (line 7). Finally all the results are reduced using the sum() operation.

Day 2 assignment

Fortunately, the first location The Historians want to search isn’t a long walk from the Chief Historian’s office.

While the Red-Nosed Reindeer nuclear fusion/fission plant appears to contain no sign of the Chief Historian, the engineers there run up to you as soon as they see you. Apparently, they still talk about the time Rudolph was saved through molecular synthesis from a single electron.

-- Day 2 - Advent of Code 2024

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