69 lines
2.1 KiB
Text
69 lines
2.1 KiB
Text
def String.words (s : String) :=
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s.split Char.isWhitespace |>.filter (¬·.isEmpty) |>.toArray
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def String.lines (s : String) :=
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s.splitOn "\n" |>.filter (¬·.isEmpty) |>.toArray
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def Array.unlines (xs : Array String) : String :=
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xs.foldl (· ++ · ++ "\n") ""
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def String.replicate : Nat → Char → String
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| 0, _ => ""
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| n+1, x => replicate n x |>.push x
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def sep (xs : Array String) (space : Fin (xs.size-1) → String)
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: String := Id.run do
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let mut out := ""
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let mut i := 0
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while h : i < xs.size do
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out := out ++ xs[i]
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if h : i < xs.size - 1 then
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out := out ++ space ⟨i, h⟩
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i := i + 1
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return out
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def justify (width : Nat) (words : Array String) : String :=
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sep words space
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where
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space i := if i.val ≤ largeSpaces then largeSpace else smallSpace
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largeSpace := smallSpace.push ' '
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smallSpace := String.replicate smallSpaceLen ' '
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smallSpaceLen := spacesNeeded / numSpaces
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largeSpaces := spacesNeeded % numSpaces
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numSpaces := words.size - 1
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spacesNeeded := width - wordsLength
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wordsLength := words.foldr (·.length + ·) 0
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def breakUp (width : Nat) (words : Array String) : Array (Array String) :=
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let (_, line, lines) := words.foldl
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(fun (left, line, lines) word =>
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if word.length < left
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then (left - (word.length + 1), line.push word, lines)
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else (width - word.length, #[word], lines.push line))
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(width, #[], #[])
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lines.push line
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def solve (width : Nat) :=
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Array.unlines ∘ Array.map (justify width) ∘ breakUp width ∘ String.words
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def usage := "Usage: justify WIDTH"
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def fail : IO UInt32 := do IO.println usage; return 1
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def main : List String → IO UInt32
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| [width] => do
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if let some width := width.toNat?
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then
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let stdin ← IO.getStdin
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let mut remainder : Array String := #[]
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repeat
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let line ← stdin.getLine
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if line.isEmpty then break
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let lines := breakUp width (remainder ++ line.words)
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if h : lines.size > 0 then
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remainder := lines[lines.size-1]
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for line in lines[0:lines.size-1] do
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IO.println <| justify width line
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IO.println <| sep remainder (fun _ => " ")
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return 0
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else fail
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| _ => fail
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