This is a compilation of my solutions to the 2019 Advent of Code competitive programming competition.
The programs are split up into days just as they are on the Advent of Code website.
Note: Although all of my files are named either part1.java or part2.java, the actual code will work only in a file named as Solution.java. This is to make it easier for you to distinguish what file accomplishes what task.
- Day 01: 0 Points, started late. ⭐⭐
- Day 02: 0 Points, started late. ⭐⭐
- Day 03: 47 Points on part 1, 0 Points on part 2 due to a bug. ⭐⭐
- Day 04: 81 Points on part 1 (20th Place!!!), 0 Points on part 2 due to small brain. ⭐⭐
- Day 05: 0 Points, absolute fail due to lots and lots of bugs :( ⭐⭐
- Day 06: 0 Points on part 1, 1 Point on part 2 (Wow! yayyy!) ⭐⭐
- Day 07: 0 Points, didn't compete as I had an IRL CS contest next day. ⭐⭐
- Day 08: 0 Points, didn't compete due to being tired. ⭐⭐
- Day 09:
- Day 11:
- Day 12:
- Day 13:
- Day 14:
- Day 15:
- Day 16:
- Day 17:
- Day 18:
- Day 19:
- Day 20:
- Day 21:
- Day 22:
- Day 23:
- Day 24:
- Day 25:
Hi! I'm Eric Wastl. I make Advent of Code. I hope you like it! I also made Vanilla JS, PHP Sadness, and lots of other things. You can find me on Twitter and GitHub.
Advent of Code is an Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like. People use them as a speed contest, interview prep, company training, university coursework, practice problems, or to challenge each other.
You don't need a computer science background to participate - just a little programming knowledge and some problem solving skills will get you pretty far. Nor do you need a fancy computer; every problem has a solution that completes in at most 15 seconds on ten-year-old hardware.
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--- General Tips --- If you get stuck, try your solution against the examples given in the puzzle; you should get the same answers. If not, re-read the description. Did you misunderstand something? Is your program doing something you don't expect? After the examples work, if your answer still isn't correct, build some test cases for which you can verify the answer by hand and see if those work with your program. Make sure you have the entire puzzle input. If you're still stuck, maybe ask a friend for help, or come back to the puzzle later. You can also ask for hints in the subreddit.
--- Frequently Asked Questions --- Why was this puzzle so easy / hard? The difficulty and subject matter varies throughout each event. Very generally, the puzzles get more difficult over time, but your specific skillset will make each puzzle significantly easier or harder for you than someone else. Making puzzles is tricky.
Why do the puzzles unlock at midnight EST/UTC-5? Because that's when I can consistently be available to make sure everything is working. I also have a family, a day job, and even need sleep occasionally. If you can't participate at midnight, that's not a problem; many people use private leaderboards to compete with people in their area.
How does authentication work? Advent of Code uses OAuth to confirm your identity through other services. When you log in, you only ever give your credentials to that service - never to Advent of Code. Then, the service you use tells the Advent of Code servers that you're really you. In general, this reveals no information about you beyond what is already public; here are examples from Reddit and GitHub. Advent of Code will remember your unique ID, names, URL, and image from the service you use to authenticate.
I find the text on the site hard to read. Is there a high contrast mode? There is a high contrast alternate stylesheet. Firefox supports these by default (View -> Page Style -> High Contrast).
I have a puzzle idea! Can I send it to you? Please don't. Because of legal issues like copyright and attribution, I don't accept puzzle ideas, and I won't even read your email if it looks like one just in case I use parts of it by accident.
--- Credits --- Puzzles, Code, & Design: Eric Wastl
Beta Testing:
Tim Giannetti Ben Lucek JP Burke Aneurysm9 Andrew Skalski Community Managers: Danielle Lucek and Aneurysm9
Playing: You!