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 22: Block Dropinator

2023-12-22

Source: Day 22: Sand Slabs

Full solution for today (spoilers!)

Part 1

Given a series of 3D blocks, allow them to fall until the simulation is stable. Any cube of a block is sufficient to support another block, ignore rotations etc.

How many blocks are not the sole supporter for any other block?

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AoC 2023 Day 20: Flip-Flopinator

2023-12-20

Source: Day 20: Pulse Propagation

Full solution for today (spoilers!)

Part 1

Simulate a virtual circuit with high and low pulses and four kinds of chips:

  • Broadcast - Re-transmit all pulses
  • Flip-flops - On a low pulse, toggle internal state; if it was on, send high; otherwise send low
  • Conjunction - Remember input from each attached module; if all inputs were high, send a low, otherwise send high
  • Output - Do nothing; just receive pulses

Count the product of low and high pulses sent after 1000 low inputs to broadcaster.

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AoC 2023 Day 19: Assembly Lininator

2023-12-19

Source: Day 19: Aplenty

Full solution for today (spoilers!)

Part 1

You are given a series of parts with 4 ratings as such:

{x=787,m=2655,a=1222,s=2876}

In addition, you are given a series of rules describing a graph as such:

px{a<2006:qkq,m>2090:A,rfg}

In this example, if you are at the node px, if a < 2006, move to qkq. Otherwise, if m > 2090 move to A. If no other case matches, the last defaults to rfg.

A and R are special cases for accept and reject.

Calculate the sum of sum of all four ratings for all nodes that end at Accept.

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