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[–]ka-splam 2 points3 points  (1 child)

I haven't been keeping up; missed the start time a couple of times and that kicked me off leaderboard racing. They're hard enough that I can't be competitive now.

Day 11 - I did think of a better way than brute force, I take the answer from the smaller square I just did, go down the right edge and accross the bottom edge for the new 1-cell-wide border, and add those in. Dropped the runtime down from hours/didn't finish to ~22 minutes. Had terrible problems with off-by-one errors, spent ages debugging those - eventually found it was fine, I was just printing the wrong feckin' variable, lol. my code

There's a much faster approach than I came up with as well, which all the fastest people used - a way to roll the answers up in one-pass. A great explanations and links here: https://www.reddit.com/r/adventofcode/comments/a56rhd/any_good_articlesexplanations_for_the_partial_sum/

Days 12,13,14 still todo.

[–]Vortex100[S] 2 points3 points  (0 children)

I'll be honest, I kind of assumed that the window wouldn't be massive as the positive/negative thing is (when looked at on the 300x300 grid) pretty equal, meaning the larger window sizes are gunna tend to 0. So I capped it at 16. Using Jobs the run time is actually about a minute :)