The earliest memory I have of ‘programming’ is in the early/mid 90s when my father brought home a computer from work. We could play games on it … so of course I took the spreadsheet program he used (LOTUS 123, did I date myself with that?) and tried to modify it to print out a helpful message for him. It … halfway worked? At least I could undo it so he could get back to work…

After that, I picked up programming for real in QBASIC (I still have a few of those programs lying around), got my own (junky) Linux desktop from my cousin, tried to learn VBasic (without a Windows machine), and eventually made it to high school… In college, I studied computer science and mathematics, mostly programming in Java/.NET, although with a bit of everything in the mix. A few of my oldest programming posts on this blog are from that time.

After that, on to grad school! Originally, I was going to study computational linguistics, but that fell through. Then programming languages (the school’s specialty). And finally I ended up studying censorship and computer security. That’s about where I am today!

But really, I still have a habit of doing a little bit of everything. Whatever seems interesting at the time!

AoC 2023 Day 17: A-Starinator

2023-12-17

Source: Day 17: Clumsy Crucible

Full solution for today (spoilers!)

Part 1

Given a grid of costs, find the shortest path from top left to bottom right. You may not double back or go straight more than 3 steps in a row.

AoC 2023 Day 16: Reflectinator

2023-12-16

Source: Day 16: The Floor Will Be Lava

Full solution for today (spoilers!)

Part 1

You are given a grid of mirrors (|-\/) and empty space (.).
Diagonal mirrors just relect the light.
The horizontal and vertical mirrors are splitters, light hitting them head on (like >|) will split to go both directions. Light hitting edge on will just go through it.
Starting in the top left going East, how many total tiles will a light beam illuminate?

AoC 2023 Day 15: Hashinator

2023-12-15

Source: Day 15: Lens Library

Full solution for today (spoilers!)

Part 1

Hash each input (comma separated) with h(v, c) = (v + c) * 17 (modulo 256 / as a byte). Sum these values.

AoC 2023 Day 14: Spininator

2023-12-14

Source: Day 14: Parabolic Reflector Dish

Full solution for today (spoilers!)

Part 1

Given a grid of # and O (among empty . points) where O can move, slide each O as far north as it can. Score each based on how far north it is.

AoC 2023 Day 13: Reflectinator

2023-12-13

Source: Day 13: Point of Incidence

Full solution for today (spoilers!)

Part 1

You are given a grid of . and #. Find the (single) axis of reflection (between two rows or columns).

AoC 2023 Day 12: Question Markinator

2023-12-12

Source: Day 12: Hot Springs

Full solution for today (spoilers!)

Part 1

Given a sequence of #.? as on, off, and unknown and a sequence of group sizes, determine how many possible arrangements there are that match the given groups.
More specifically, if you have ???.## 1,2 you need a single # and a set of two ##, there are three possibilities: #...###, .#..###, and ..#.###.

AoC 2023 Day 11: Big Banginator

2023-12-11

Source: Day 11: Cosmic Expansion

Full solution for today (spoilers!)

Part 1

Read a grid of # (stars) and . (empty space). For each completely empty line or row, add another. Calculate the sum of the Manhattan distances between all pairs of stars.

AoC 2023 Day 10: Pipinator

2023-12-10

Source: Day 10: Pipe Maze

Full solution for today (spoilers!)

Part 1

You are given as input an ASCII art pipe diagram with straight pipes |-, right angle turns LJ7F, ground ., and a start tile S.
The start tile will be part of a loop of pipes.
Find the distance to the furthest connected pipe segment from S (or half the length of the loop).

AoC 2023 Day 9: Stackinator

2023-12-09

Source: Day 9: Mirage Maintenance

Full solution for today (spoilers!)

Part 1

Given a list of terms, repeatedly calculate the differences of terms until these differences are 0. So:
0   3   6   9  12  15
  3   3   3   3   3
    0   0   0   0
Calculate the sum of next terms for each sequence (18 for this one).

AoC 2023 Day 8: Mazinator

2023-12-08

Source: Day 8: Haunted Wasteland

Full solution for today (spoilers!)

Part 1

Given a (repeated) sequence of moves (L for left and R for right) and a directed graph where each node has two neighbors (left and right), count how many total steps it takes to get from the node AAA to the node ZZZ. The sequence of moves can (and will) need to repeat.