Day 5: Print Queue

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[-] mykl@lemmy.world 4 points 1 week ago

Uiua

Well it's still today here, and this is how I spent my evening. It's not pretty or maybe even good, but it works on the test data...

spoiler

Uses Kahn's algorithm with simplifying assumptions based on the helpful nature of the data.

Try it here

Data ← ⊜(□)⊸≠@\n "47|53\n97|13\n97|61\n97|47\n75|29\n61|13\n75|53\n29|13\n97|29\n53|29\n61|53\n97|53\n61|29\n47|13\n75|47\n97|75\n47|61\n75|61\n47|29\n75|13\n53|13\n\n75,47,61,53,29\n97,61,53,29,13\n75,29,13\n75,97,47,61,53\n61,13,29\n97,13,75,29,47"
Rs   ← ≡◇(⊜⋕⊸≠@|)▽⊸≡◇(⧻⊚⌕@|)Data
Ps   ← ≡⍚(⊜⋕⊸≠@,)▽⊸≡◇(¬⧻⊚⌕@|)Data

NoPred  ← ⊢▽:⟜(≡(=0/+⌕)⊙¤)◴♭⟜≡⊣                # Find entry without predecessors.
GetLead ← ⊸(▽:⟜(≡(¬/+=))⊙¤)⟜NoPred             # Remove that leading entry.
Rules   ← ⇌⊂⊃(⇌⊢°□⊢|≡°□↘1)[□⍢(GetLead|≠1⧻)] Rs # Repeatedly find rule without predecessors (Kaaaaaahn!).

Sorted   ← ⊏⍏⊗,Rules
IsSorted ← /×>0≡/-◫2⊗°□: Rules
MidVal   ← ⊡:⟜(⌊÷ 2⧻)

⇌⊕□⊸≡IsSorted Ps        # Group by whether the pages are in sort order.
≡◇(/+≡◇(MidVal Sorted)) # Find midpoints and sum.

[-] CameronDev@programming.dev 3 points 1 week ago

Does this language ever look pretty? Great for signaling UFOs though :D

[-] mykl@lemmy.world 2 points 1 week ago

Ah, but the terseness of the code allows the beauty of the underlying algorithm to shine through :-)

[-] hades@lemm.ee 2 points 1 week ago

Those unicode code points won't use themselves.

[-] mykl@lemmy.world 2 points 1 week ago* (last edited 1 week ago)

Oh my. I just watched yernab's video, and this becomes so much easier:

# Order is totally specified, so sort by number of predecessors,
# check to see which were already sorted, then group and sum each group.
Data ← ⊜(□⊜□⊸≠@\n)⊸(¬⦷"\n\n")"47|53\n97|13\n97|61\n97|47\n75|29\n61|13\n75|53\n29|13\n97|29\n53|29\n61|53\n97|53\n61|29\n47|13\n75|47\n97|75\n47|61\n75|61\n47|29\n75|13\n53|13\n\n75,47,61,53,29\n97,61,53,29,13\n75,29,13\n75,97,47,61,53\n61,13,29\n97,13,75,29,47"
Rs   ← ≡◇(⊜⋕⊸≠@|)°□⊢Data
Ps   ← ≡⍚(⊜⋕⊸≠@,)°□⊣Data
⊕(/+≡◇(⊡⌊÷2⧻.))¬≡≍⟜:≡⍚(⊏⍏/+⊞(∈Rs⊟)..).Ps

this post was submitted on 05 Dec 2024

26 points (100.0% liked)

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