ReadInt ⇐ (+ ⟜ (10⊸×))´ ∘ (-⟜'0') ∘ ⌽
IntFile ⇐ ReadInt¨ •FLines

aoc1 ⇐ {
  A ⇐ +´ ∘ (>⟜(∞⊸»)) ∘ IntFile
  B ⇐ +´ ∘ (>⟜(∞⊸»)) ∘ (+´˘) ∘ (3⊸↕) ∘ IntFile
}

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Split  ⇐ ((+`׬) - ⊢)∘= ⊔ ⊢  # from bqn crates lmao
Words  ⇐ ((0≠≠)¨⊸/) ∘ (' '⊸Split)
CSV    ⇐ ','⊸Split
CSVInt ⇐ ReadInt¨ CSV

aoc2 ⇐ {
  Move1 ← { "forward" 𝕊 x: x‿0; "down" 𝕊 y: 0‿y; "up" 𝕊 y: ⟨0,-y⟩ }
  Move ← Move1⟜ReadInt´ ∘ Words
  MoveFile ← Move¨ ∘ •FLines
  DoMoveB ← {dx‿da 𝕊 x‿y‿a : ⟨x+dx, y+(dx×a), a+da⟩}

  A ⇐ ×´ +´ ∘ MoveFile
  B ⇐ ×´ ∘ (2⊸↑) ∘ (0‿0‿0⊸(DoMoveB´)∘⌽) ∘ MoveFile
}

################################################################################

FromBin ⇐ +´ 2⊸⋆∘↕∘≠ × ⌽
BitFile ⇐ (-⟜'0') ∘ > ∘ •FLines

aoc3 ⇐ {
  Most ← ⊑ ∘ ((⍒⊒) ⊸ ⊏)
  Gamma ← Most˘ ∘ ⍉ ∘ BitFile

  A ⇐ ¬⊸(×○FromBin) ∘ Gamma
}

################################################################################

aoc4 ⇐ {
  BingoFile ← {
    lines ← •FLines 𝕩
    picks ⇐ CSVInt ⊑lines
    boards ⇐ ReadInt¨ > Words¨ 1⊸↓˘ ∘‿6 ⥊ 1↓lines
    states ⇐ boards <⊸(≡◶⊣‿0¨`) picks
  }

  Win ← ∨´ ((∧´ 0⊸≡)˘)∘(⍉∾⊢)
  Score ← +´⥊

  A ⇐ {
    picks‿states ← BingoFile 𝕩
    ⊑ 0⊸≠⊸/ +´¨ picks × (Score × Win)˘¨ states
  }

  B ⇐ {
    picks‿states ← BingoFile 𝕩
    pick‿cur‿prev ← ⊑ ((∧´ Win˘)¨ states) / (picks ∾¨ states ⋈¨ »states)
    pick × Score (¬Win˘ prev) / cur
  }
}

################################################################################

aoc5 ⇐ {
  VentFile ← ReadInt¨∘∾∘(CSV¨ 0‿2⊸⊏)∘Words¨ •FLines
  To ← {𝕨≡𝕩? 𝕩; ⌽⍟(𝕨>𝕩) (𝕨⌊𝕩) ↓ ↕(1+𝕨⌈𝕩)}
  DrawLine ← {x1‿y1‿x2‿y2: (x1 To x2) ⋈¨ (y1 To y2)}
  Orth ← {∨´ =´ <˘ 2‿∘ ⥊ 𝕩}
  Danger ← {1⊑ /⁼ ⊒ ∾DrawLine¨ 𝕩}
  A ⇐ Danger (Orth¨⊸/ VentFile), B ⇐ Danger VentFile
}

################################################################################

aoc6 ⇐ {
  FishFile ← /⁼∘CSVInt∘⊑∘•FLines
  Step ← (⊑ × (/⁼6‿8)˙) +○(9⊸↑) «
  Fishies ← {+´ Step⍟𝕨 FishFile 𝕩}
  A ⇐ 80⊸Fishies, B ⇐ 256⊸Fishies
}

################################################################################

aoc7 ⇐ {
  CrabFile ← CSVInt∘⊑∘•FLines

  Range ← {l + ↕(⌈´𝕩)¬(l←⌊´𝕩)}

  FuelA ← +´              ∘| -
  FuelB ← +´∘(÷⟜2)∘(⊢×+⟜1)∘| -

  _Go ← {⌊´ ps⊸𝔽¨ Range ps←CrabFile 𝕩}
  A ⇐ FuelA _Go, B ⇐ FuelB _Go
}