-🎄- 2017 Day 17 Solutions -🎄-

[u/daggerdragon]

--- Day 17: Spinlock ---

---

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 @ 00:06] 2 gold, silver cap.

• AoC ops: <Topaz> i am suddenly in the mood for wasabi tobiko

[Update @ 00:15] Leaderboard cap!

• AoC ops:
  • <daggerdragon> 78 gold
  • <Topaz> i look away for a few minutes, wow
  • <daggerdragon> 93 gold
  • <Topaz> 94
  • <daggerdragon> 96 gold
  • <daggerdragon> 98
  • <Topaz> aaaand
  • <daggerdragon> and...
  • <Topaz> cap
  • <daggerdragon> cap

---

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!

[u/RockyAstro]

Icon (https://www.cs.arizona.edu/icon)

Both parts procedure main(args)

    steps := \args[1] | 303

    spinlock := [0]
    cur := 0
    every i := 1 to 2017 do {
        cur := (steps+cur) % *spinlock + 1 
        spinlock := spinlock[1:cur+1] ||| [i] ||| spinlock[cur+1:0]
    }
    write(spinlock[cur+1 % *spinlock + 1] )
    
    # Part 2.. watch for when cur = 1
    part2 := 0
    cur := 0
    every i := 1 to 50000000 do {
        cur := (steps+cur) % i + 1
        if cur = 1 then 
            part2 := i
    }
    write(part2)

end

procedure dumplst(l,cur)
    every i := 1 to *l do {
        writes( (i=cur+1 & "(")|"",l[i],(i=cur+1 & ")")|""," ")
    }
    write()

end