Day five's problem is a nice one for an early CS class. It can be very much brute forced but it also touches on some nice concepts and can be solved pretty elegantly. I've embedded a walk through in Clojure at the end but a Python solution would be pretty similar. Read the problem over if you haven't. At it's core you are taking a boarding pass representing a coded airplane seat number and you're converting it to a known seat (row and column).

One of the nice things about Advent of Code is that it gets me to explore language features I haven't used yet. Today's problem got me to explore Clojure Spec which is a very cool validation library. There's a complete run through of the solution in Clojure in the video but here I'll talk about the problem in Python (mostly). Today's problem is about validating passports. You start with a text file consisting of passport information.

I thought I'd do a video for today. No particular reason. Mostly why not. I'll talk about day 3's problem and code up a solution in Clojure. If you haven't ever used Clojure, hopefully this will give a bit of the flavor. This video also serves double duty as being my next Using Emacs video since it demos Emacs's Clojure tools. Mostly Cider which even with a few quirks is the best development environment I've ever used.

Day two introduced some staples of staples of not only Advent of Code but also of programming problems in general. The first is input parsing. For this problem you get lines of input like this: 1-3 a: abcde 1-3 b: cdefg 2-9 c: cccccccc or in general number_1-number_2 Letter: String There are a few ways to handle this. One is to brute force it. In Python maybe something like: sample_line="4-15 f: abcdefg" sample_list = sample_line.

So, yesterday I was chatting with my daughter. She was talking with her team and for some reason one of them pulled out an interview question from their company's question bank. Turns out it was today's Advent of Code problem. As with past years, I'm going to try to solve the problems in Clojure but if I can will talk Python when I talk about solutions. Part 1 of the problem basically asks for you to find a pair of numbers in an array that sum to a specific value.

Tomorrow, or more practically, tonight at Midnight, Eric Wastl will once again launch the Advent of Code. As I've written before, it's a month long event where each day a new programming problem is released. The problems range in difficulty and complexity. Some are very approachable to beginners and some are crazy challenging. I've written a bunch about AOC in past years: Solve A to Solve B Data structures and Hidden Complexity Tools can shape- how we think 2019 day 1 2019 day 2 2019 day 3 2019 day 4 2019 day 8 2019 day 8 addendum and a few more not listed.