adotsch / aoc

Advent of Code solutions in KDB/Q

Advent of Code solutions

This repository contains my Q solutions to the Advent of Code puzzles of year 2015, 2016, 2020, 2021, 2022 and 2023.

Cheating

This repository is not intended to promote or otherwise encourage cheating.

If you are competing you should always submit your results based on your own work.

Other solutions in K/Q/APL

Repsitory	Language
Pavlo Piatkovskyi	Q
Mark Street	Q
Cillian Reilly	Q
Sean Ang	Q
avkoshel	Q
Tadhg Downey	Q
lukebrit27	Q
Angus Wilson	Q
Péter Györök	Q
Rory Kemp	K/Q, APL
Nick Nickolov (NGN)	K
Aaron W. Hsu	APL
Stefan Kruger	APL
Peter Vernigorov	APL/K

aoc's Issues

day 11

you can use arthur's sparse.q
to create the same table you have, but marching over the matrix all at the same time should be the fastest by of finding neighbors.
sm:{([]row:where count each i;col:raze i;val:raze x@'i:where each x<>0)}

c:raze "L"=i;l:raze "#"=i;
s:{(count x;count first x)} i
d:{x!s sv flip x}flip s vs til prd s
p:flip key d
m:{{?[c y;y;d flip x+s vs y]}[x]/[d flip x+y]}
n:(1_{x cross x}0 1 -1) m: p
seat:{c*(5>a)&x|0=a:sum 0^x n}
sum seat over l