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… before taking a hard turn into the private sector to follow my PhD advisor.

Since then, I’ve worked in the computer security space at a couple of different companies. Some don’t exist any more, some you’ve probably heard of. I still program for fun too, and not just in security.

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

AoC 2021 Day 3: Binary Contraption

2021-12-03

Source: Binary Diagnostic

Part 1: Given a list of binary numbers, calculate gamma such that each bit is the most common bit in that position in the input and epsilon which is the binary inverse of gamma. Return the product.

AoC 2021 Day 2: Submarine Simulator

2021-12-02

Source: Dive!

Part 1: Simulate a submarine with 3 commands: `forward N`, `down N`, and `up N` that move forward, increase depth, and decrease depth in that order. Calculate the product of the final position and depth.

AoC 2021 Day 1: Depth Finder

2021-12-01

Source: Depth Finder

Part 1: Given a list of numbers, count how many times sequential numbers increase.

Advent of Code 2021

2021-12-01

Been a while since I’ve done an advent of code! I’ll probably backfill a few years eventually, but for now, let’s just write some code!

As always, these problems are wonderful to try to solve yourself. If you agree, stop reading now. This post isn’t going anywhere.

If you’d like to see the full form of any particular solution, you can do so on GitHub (including previous years and possibly some I haven’t written up yet): jpverkamp/advent-of-code

Neural Network Cellular Automata

2021-09-06

Okay. A random post on the /r/cellular_automata subreddit inspired me.

Let’s generate a cellular automata where each pixel updates based on a neural network given as input:

The x/y coordinates (scaled to the range 0-1)
An optional random value (to make it more dynamic)
A variety of neighboring data, such as:
- The number of neighbors that are ‘active’ (> 50% white), ranges 0-8 scaled to 0-1. This should allow Conway's Game of Life
- The RGB values of all neighbors (allows a superset of the above)
- Gradients, subtract color value of the left from the right so that you get edges and side to side movement

Let’s do it!

Solving Snakebird

2021-08-18

Snakebird!

A cute little puzzle game, where you move around snake(birds). Move any number of snakes around the level, eating fruit, and getting to the exit. The main gotchas are that you have gravity to content with–your snake will easily fall off the edge of the world–and each time you eat a fruit, your snake gets bigger. This can help get longer to get into hard to reach places or it can cause trouble when you trap yourself in corners.

Let’s use the new immutable.js solver to solve these problems!

Immutable.js Solvers

2021-08-17

A bit ago I wrote about writing a generic brute force solver (wow, was that really two months ago?). It got … complicate. Mostly, because every time I wrote a step function, I had to be careful to undo the same. Wouldn’t it be nice if we could just write a step function and get backtracking for ‘free’?

Well, with immutability you can!

Splitting Images

2021-08-10

I recently came across a problem where I had a single image with a transparent background containing multiple images that I wanted to split into their component parts. For example, split this:

Into these:

raco pkg install noise

2021-08-05

What feels like a million years and a lifetime ago, I wrote up a library for perlin and simple noise in Racket. Inspired by Jens Axel Søgaard’s new Sketching library (processing in Racket) and a conversation thereabout, I figure it’s about time to push noise to the raco package manager!

Crosslinks by Title in Hugo

2021-07-15

Another quick Hugo post. One thing I miss about my previous blogging platform(s) was the ability to generate quick links between posts just by using the title of the post. So rather than this:

a cool post

This is [a cool post]({{< ref "2021-07-15-crosslinks-by-title-in-hugo" >}}), go read it.

You could do this:

This is {{< crosslink title="Crosslinks by Title in Hugo" text="a cool post" >}}.

Or shorter: {{< crosslink "Crosslinks by Title in Hugo" >}}.

And it should just work.

Source: Binary Diagnostic

Part 1: Given a list of binary numbers, calculate gamma such that each bit is the most common bit in that position in the input and epsilon which is the binary inverse of gamma. Return the product.

Source: Dive!

Part 1: Simulate a submarine with 3 commands: forward N, down N, and up N that move forward, increase depth, and decrease depth in that order. Calculate the product of the final position and depth.

Source: Depth Finder

Part 1: Given a list of numbers, count how many times sequential numbers increase.

Part 1: Simulate a submarine with 3 commands: `forward N`, `down N`, and `up N` that move forward, increase depth, and decrease depth in that order. Calculate the product of the final position and depth.