APL

corristo@programming.dev · 7 months ago

APL

I finally managed to make use of ⍣ :D

input←⊃⎕NGET'inputs/day9.txt'1
p←{⍎('¯'@((⍸'-'∘=)⍵))⍵}¨input
f←({⍵⍪⊂2-⍨/⊃¯1↑⍵}⍣{∧/0=⊃¯1↑⍺})
⎕←+/{+/⊢/¨f⊂⍵}¨p ⍝ part 1
⎕←+/{-/⊣/¨f⊂⍵}¨p ⍝ part 2

corristo@programming.dev · edit-2 7 months ago

APL

I'm using this year's AoC to learn (Dyalog) APL, so this is most likely a pretty terrible solutions. I would've liked to use ⍣ instead of of my imitation of a while loop with a recursive function, but I couldn't figure out how to get to the number of iterations ⍣ performed to arrive at the destination. If someone here knows how to do that (or has other suggestions for improvement) I'm open for suggestions.

⎕IO ← 0       ⍝ use 0-based indexes
I←⌷⍨∘⊃⍨⍤0 99  ⍝ "sane" indexing
⎕PP←17        ⍝ print integers with up to 17 significant digits without use of scientific notation

input←⊃⎕NGET'inputs/day8.txt'1
instructions←⊃input
p←↑{0 2 4 I{6⍴⎕CSV⍠'Widths'(3 4 3 2 3 1)⊢⍵'S'1}⍵}¨ 2↓input
nodes←,1↑[1]p
L←(⍳⍴nodes) ∘.{nodes[⍺]≡⍵ 1 ⌷p} ⍳⍴nodes
R←(⍳⍴nodes) ∘.{nodes[⍺]≡⍵ 2 ⌷p} ⍳⍴nodes
S←(⊃(+.×)/{'R'≡⍵:R ⋄ ⍵≡'L':L}¨⌽instructions)
⎕←(≢instructions) × {⍺←0 ⋄ ⍵[⍸'ZZZ'∘≡¨nodes]: ⍺ ⋄ ⍺+1 ∇ S+.×⍵}'AAA'∘≡¨nodes                             ⍝ part 1
⎕←∧/(≢instructions) × {⍺←0 ⋄ 0≡+/⍵[⍸~('Z'∘=⊢/)¨nodes]: ⍺ ⋄ ⍺+1 ∇ S+.×⍵}¨{(⍳≢nodes)=⍵}¨⍸('A'∘=⊢/)¨nodes  ⍝ part 2

corristo@programming.dev · edit-2 7 months ago

APL

I'm using this years' AoC to learn (Dyalog) APL, so this is probably terrible code. I'm happy to receive pointers for improvement, particularly if there is a way to write the same logic with tacit functions or inner/outer products that I missed.

input←⊃⎕NGET'inputs/day4.txt'1
num_matches←'Card [ \d]+: ([ 0-9]+) \| ([ 0-9]+)'⎕S{≢↑∩/0~⍨¨{,⎕CSV⍠'Separator' ' '⊢⍵'S'3}¨⍵.(1↓Lengths↑¨Offsets↓¨⊂Block)} input
⎕←+/2*1-⍨0~⍨num_matches ⍝ part 1
⎕←+/{⍺←0 ⋄ ⍺=≢⍵:⍵ ⋄ (⍺+1)∇⍵ + (≢⍵)↑∊((⍺+1)⍴0)(num_matches[⍺]⍴⍵[⍺])((≢⍵)⍴0)}(≢num_matches)⍴1 ⍝ part 2