Note: This topic is to talk about Day 9 of the Advent of Code 2019 . There is a private leaderboard for elixirforum members. You can join it by following this link and entering the following code: 39276-eeb74f9a

Nothing too exciting in my code here . My intcode computer has overall been a bit of a mess due to not going back and cleaning it up. This problem really showed some issues in how I had implicit rules baked into my code. I was not putting arg 3 through any type of mode checking, because it was alway…

I got top 80-90! Here is the meat of my solution . I specifically designed my intcode interpreter to allow rapid extension of it, I even spent an hour cleaning it up the other day, seems like that paid off. It’s pretty cool to see how well a recursive interpreter of a self-modifying memory/code VM …

[image] mason-bially: I got top 80-90! Wow!!! Great work. That’s super speedy. [image] mason-bially: I would also be curious about the timings people got on the second part. Mine was 3.860 seconds (timed from the shell). I’m honestly surprised here. I feel like I didn’t do anything sp…

To be clear I have used elixir less than a week and know nearly nothing about optimizing it (or erlang), I use advents of code to learn new languages. I was worried a list would be too slow because of the O(n) access and couldn’t find good information on optimization. I figured the erlang :array wo…

[image] mason-bially: I would also be curious about the timings people got on the second part. Mine was 3.860 seconds (timed from the shell) Both parts finish in 0.1 seconds: $ mix test ... Finished in 0.1 seconds 3 tests, 0 failures

Looking at your code I feel like an idiot for missing that I can use the function pattern matching as a sort of multi-method. I may need to do some additional refactoring. I’ll still have to always write a forwarding method, but it might make it a cleaner copy paste in the end rather than doing wha…

[image] mason-bially: Could you point me to the documentation for what you are describing? Hm, I’m wrong here. I tried to do a benchmark with :array.get and :array.set vs Map functions and they were about the same. I’m not sure why it would be so much slower without digging in more.

I suspect my use of .exs and dynamically loading my libraries with Code.require_file("../day07/el.ex", __DIR__) might have something to do with it. I haven’t learned mix yet… Anyway thanks for the feed back! It was very useful. Edit: some other possible reasons: Pattern matches (wide ones too) …

This is my solution. So far I strived to keep the code clean, and this payed off, b/c the changes to the machine code were minimal. I finally extracted Intcode interpreter into a separate module, but I still keep that module code in the same file as the solution, so others can easily read the entire…

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Advent of Code 2019 - Day 9

Learning Resources Coding Challenges

bjorng December 9, 2019, 6:01am 2

Here is my solution.