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Advent of Code 2021 - Day 9

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bjorng

bjorng

Erlang Core Team

Advent of Code 2021 - Day 9

This topic is about Day 9 of the Advent of Code 2021 .

We have a private leaderboard (shared with users of Erlang Forums):

https://adventofcode.com/2021/leaderboard/private/view/370884

The entry code is:
370884-a6a71927

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bjorng

bjorng

Erlang Core Team

I solved part two with a simple union-find algorithm. Since it finished in less than two seconds on my computer, I didn’t need to do any further optimizations.

https://github.com/bjorng/advent-of-code-2021/blob/49f0d8eff0110e6e5d823bf314236c6bf7dcc991/day09/lib/day09.ex

4
Post #2
deadbeef

deadbeef

For part two I did a sort-of breadth-first search (I think?). Feels a bit messy, but got the job done.
Also, felt my file’s a bit cruft-y with how many small functions I made, but was trying to make things reusable between parts.

https://github.com/ed-flanagan/advent-of-code-solutions-elixir/blob/main/lib/advent/y2021/d09.ex

1
Post #3
wasi0013

wasi0013

Here’s my solution: y2021/day_09.ex
For part 2 used bfs

1
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