challenge-281/conor-hoekstra/ch-2.bqn


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# For up to date code:
# https://github.com/codereport/bqn-code/blob/main/pwc/281-2.bqn

Convert ← 48|-⟜'0'¨
deltas  ← (⌽¨⊸∾)∾<˘2‿¯2⋈⌜1‿¯1
IsValid ← ∧´1⊸≤∧8⊸≥
Moves   ← {IsValid¨⊸/⥊𝕩+⌜deltas}

MinKnightMoves ← {
    end‿start ← 𝕨 ⋈○Convert 𝕩
    1 end { ∨´𝕗⊸≡¨Moves 𝕩 ? 𝕨 ; (𝕨+1) 𝕊 Moves 𝕩 } ⟨start⟩
}

# Tests
•Show "g2" MinKnightMoves "a8" # 4
•Show "g2" MinKnightMoves "h2" # 3