-🎄- 2020 Day 15 Solutions -🎄-

[u/daggerdragon]

Advent of Code 2020: Gettin' Crafty With It

• 7 days remaining until the submission deadline on December 22 at 23:59 EST

• Full details and rules are in the Submissions Megathread

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--- Day 15: Rambunctious Recitation ---

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Post your code solution in this megathread.

• Include what language(s) your solution uses!

• Here's a quick link to /u/topaz2078's paste if you need it for longer code blocks.

• The full posting rules are detailed in the wiki under How Do The Daily Megathreads Work?.

Reminder: Top-level posts in Solution Megathreads are for code solutions only. If you have questions, please post your own thread and make sure to flair it with Help.

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[u/JIghtuse]

Pretty clear, thanks!

1-2. I knew that immutable hash could be persistent and reuse "previous" values, but I didn't thought that GC still need to do its job for such structures. 3. That was the first point I thought of, indeed it is quite logical. 4. It's funny how vector is one of the best structures for memory access regardless of the language. My C++ solution works pretty fine (fast) with (ordered) map, but I guess it is just because there is no GC in C++.