Day 08: Haunted Wasteland — day08 • aocR

Usage

f08a(x)

f08b(x)

example_data_08(example = 1)

Arguments

x: some data
example: Which example data to use (by position or name). Defaults to 1.

Value

For Part One, f08a(x) returns .... For Part Two, f08b(x) returns ....

Details

Part One

You\'re still riding a camel across Desert Island when you spot a sandstorm quickly approaching. When you turn to warn the Elf, she disappears before your eyes! To be fair, she had just finished warning you about ghosts a few minutes ago.

One of the camel\'s pouches is labeled \"maps\" - sure enough, it\'s full of documents (your puzzle input) about how to navigate the desert. At least, you\'re pretty sure that\'s what they are; one of the documents contains a list of left/right instructions, and the rest of the documents seem to describe some kind of network of labeled nodes.

It seems like you\'re meant to use the left/right instructions to navigate the network. Perhaps if you have the camel follow the same instructions, you can escape the haunted wasteland!

After examining the maps for a bit, two nodes stick out: AAA and ZZZ. You feel like AAA is where you are now, and you have to follow the left/right instructions until you reach ZZZ.

This format defines each node of the network individually. For example:

RL

AAA = (BBB, CCC)
BBB = (DDD, EEE)
CCC = (ZZZ, GGG)
DDD = (DDD, DDD)
EEE = (EEE, EEE)
GGG = (GGG, GGG)
ZZZ = (ZZZ, ZZZ)

Starting with AAA, you need to look up the next element based on the next left/right instruction in your input. In this example, start with AAA and go right (R) by choosing the right element of AAA, CCC. Then, L means to choose the left element of CCC, ZZZ. By following the left/right instructions, you reach ZZZ in 2 steps.

Of course, you might not find ZZZ right away. If you run out of left/right instructions, repeat the whole sequence of instructions as necessary: RL really means RLRLRLRLRLRLRLRL... and so on. For example, here is a situation that takes 6 steps to reach ZZZ:

LLR

AAA = (BBB, BBB)
BBB = (AAA, ZZZ)
ZZZ = (ZZZ, ZZZ)

Starting at AAA, follow the left/right instructions. How many steps are required to reach ZZZ?

Part Two

(Use have to manually add this yourself.)

(Try using convert_clipboard_html_to_roxygen_md())

Examples

f08a(example_data_08(1))
#> [1] 2
f08a(example_data_08(2))
#> [1] 6
f08b(example_data_08(3))
#> [1] 6