Learning Resources>Coding Challenges

Avent of Code 2020 - Day 23

#2020#advent-of-code
Papey

Papey

Avent of Code 2020 - Day 23

This topic is about Day 23 of the Advent of Code 2020 .

Thanks to @egze, we have a private leaderboard:
https://adventofcode.com/2020/leaderboard/private/view/39276

The join code is:
39276-eeb74f9a

11 comments
#2020#advent-of-code
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bjorng

bjorng

Erlang Core Team

Getting rid of the back links reduced the running time from 80 seconds to 40 seconds on my computer as well as simplifying the code. I didn’t bother doing any more optimizations.

My implementation takes 22 seconds on my machine, so I’m interested if anyone got good performance without resorting to native code.

I have not tried it myself, but I would expect that using the atomics module would give a nice speedup.

3
Post #10
bjorng

bjorng

Erlang Core Team

That is 2.7 seconds on my computer. Nice! :+1: :rocket:

2
Post #11
hvnsweeting

hvnsweeting

Part 1 is simple with list but that would take forever to run part 2. I also tried paper and pencil to calculate as it seems to have some pattern, failed to this. Then I tried to speed up code of part 1,end up implementing a fast linked list.

1
Post #3
cblavier

cblavier

Well done @bossek, I had an impressive performance bump when switching from Map to :atomics (from 40sec to 2sec)

Here is my refactoring commit. Impressed on how such a few line change can make a big difference.

1
Post #12

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