18 lines
598 B
BQN
18 lines
598 B
BQN
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⟨SplitOn,ReadDec⟩ ← •Import "../../lib.bqn"
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i ← ReadDec⌾(1⊸⊑)¨ (<' ')⊸SplitOn¨ •FLines "input"
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UnitDelta ← (⊢÷(|+0⊸=))
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ExpandStep ← {
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𝕊 "L"‿l: 𝕊 (-l)‿0;
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𝕊 "R"‿r: 𝕊 r‿0;
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𝕊 "U"‿u: 𝕊 0‿u;
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𝕊 "D"‿d: 𝕊 0‿(-d);
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𝕊 delta: ((⌈´|)⥊<∘UnitDelta) delta
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}
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Step ← {knots 𝕊 delta: {h 𝕊 t: (UnitDelta h-t) +⍟(1<⌈´|h-t) t}` (delta⊸+)⌾⊑ knots}
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Visited ← {+´0=⊒(¯1⊸⊑)¨(<𝕨⥊<0‿0) Step` ∾ExpandStep¨ 𝕩}
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•Out "day09.1: "∾•Fmt 2 Visited i
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•Out "day09.2: "∾•Fmt 10 Visited i
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