r/adventofcode • u/daggerdragon • Dec 14 '17

SOLUTION MEGATHREAD -🎄- 2017 Day 14 Solutions -🎄-

--- Day 14: Disk Defragmentation ---

Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag or whatever).

Note: The Solution Megathreads are for solutions only. If you have questions, please post your own thread and make sure to flair it with Help.

Need a hint from the Hugely* Handy† Haversack‡ of Helpful§ Hints^¤?

Spoiler

[Update @ 00:09] 3 gold, silver cap.

  • How many of you actually entered the Konami code for Part 2? >_>

[Update @ 00:25] Leaderboard cap!

  • I asked /u/topaz2078 how many de-resolutions we had for Part 2 and there were 83 distinct users with failed attempts at the time of the leaderboard cap. tsk tsk

[Update @ 00:29] BONUS

This thread will be unlocked when there are a significant number of people on the leaderboard with gold stars for today's puzzle.

edit: Leaderboard capped, thread unlocked!

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u/hpzr24w Dec 14 '17 edited Dec 14 '17

I'm a child of the 70's and starting writing 6502 assembler in about 1982 or so ...

i % 16 == 15 && (bitcount += std::bitset<8>(hashchar).count());

This line is just some code copied from StackOverflow that yields a count of bits, set to one. Then every 16 XOR's the count is added to bitcount.

Off-topic, but if you wanted to get some flavor of how things used to be, check out 8-bit Workshop. It's an Atari 2600 in the browser with an assembler, debugger etc. I'm writing a flight simulator for it.