This was a good year, in my opinion. It was a return to the 2015-2017
era, before the unfortunate experiment in collective puzzle-making in
2018, and the “armature” of the intcode puzzles in 2019. These were
fun, and impressive, but if you missed out on doing them there was
~45% of the puzzles gone.
I managed to solve all puzzles before the end of the year, with a personal score of 48 out of 50, which is the best I’ve done since 2016.
AoC has grown hugely, even compared to last year. Here’s how many solved both parts of day 1 and day 25 (essentially solving every puzzle):
| Year | 2 stars day 1 | 2 stars day 25 | Personal best ranking for 2 stars |
|---|---|---|---|
| 2015 | 50 358 | 3 521 | 422 (day 16) |
| 2019 | 101 125 | 3 137 | 2 111 (day 23) |
| 2020 | 148 468 | 11 285 | 5 040 (day 18) |
Favorite puzzle was probably day 20, where we had to do some image recognition. I didn’t finish this on the day it was released but had some fun polishing it later.