bomb.fs
let WIDTH = 6
let HEIGHT = 5

type Matrix =
  struct
    val D : uint32
    new (d) = {D = d}
    new (s:string) = {D = System.Convert.ToUInt32(s,16)}
    new (x,y) =
      {D = 1u <<< (31 - x - (y * WIDTH))}
    member this.At(x,y) =
      (this.D >>> (31 - x - (y * WIDTH))) % 2u > 0u
    override this.ToString() =
      this.D.ToString("x8")
    static member (+) (m1: Matrix, m2: Matrix) =
      new Matrix(m1.D ||| m2.D)
    static member Zero = new Matrix()
  end

let toRow y (m:Matrix) =
  Array.map (fun x -> m.At(x,y)) [|0..WIDTH-1|]
let fromRow y (r:bool array) =
  [0..WIDTH-1]
  |> List.filter (fun x -> r.[x])
  |> List.sumBy (fun x -> new Matrix(x,y))
let toColumn x (m:Matrix) =
  Array.map (fun y -> m.At(x,y)) [|0..HEIGHT-1|]
let fromColumn x (c:bool array) =
  [0..HEIGHT-1]
  |> List.filter (fun y -> c.[y])
  |> List.sumBy (fun y -> new Matrix(x,y))
let blast1D x (w:bool array) =
  let outofRange i = (i < 0) || (Array.length w <= i)
  let rec indexOfWall d i =
    if outofRange i || w.[i] then i else indexOfWall d (i+d)
  let w1 = indexOfWall -1 (x-1)
  let w2 = indexOfWall 1 (x+1)
  Array.map (fun i -> w1 < i && i < w2) [|0..Array.length w - 1|]
let blast2D (w:Matrix) x y =
  let h = w |> toRow y |> blast1D x |> fromRow y
  let v = w |> toColumn x |> blast1D y |> fromColumn x
  h + v
let blast (w:Matrix) (b:Matrix) =
  seq {for x in 0..WIDTH-1 do
       for y in 0..HEIGHT-1 do
       yield (x,y)}
  |> Seq.filter b.At
  |> Seq.sumBy (fun (x,y) -> blast2D w x y)
let solve (s:string) =
  let a = s.Split([|'/'|])
  let b = blast (new Matrix(a.[0])) (new Matrix(a.[1]))
  b.ToString()

(* for test *)

type TestResult = Success | Failure

let test target expected =
  let actual = solve target
  printfn "%A" (if expected = actual then Success else Failure)

[<EntryPoint>]
let main args =
  test "802b1200/01400c20" "53c40cfc"
  test "28301068/84080504" "d64fef94"
  test "100a4010/80010004" "e241850c"
  test "81020400/000000fc" "0e3cfbfc"
  test "80225020/7e082080" "7fdd24d0"
  test "01201200/40102008" "fe1861fc"
  test "00201000/01000200" "43c48f08"
  test "00891220/81020408" "ff060c1c"
  test "410033c0/0c300000" "3cf0c000"
  test "00000000/01400a00" "7bf7bf78"
  test "00000000/20000a00" "fca2bf28"
  test "00000000/00000000" "00000000"
  test "00cafe00/00000000" "00000000"
  test "aaabaaaa/50000000" "51441040"
  test "a95a95a8/56a56a54" "56a56a54"
  test "104fc820/80201010" "ea30345c"
  test "4a940214/05000008" "05000008"
  test "00908000/05000200" "ff043f48"
  test "00c48c00/fe1861fc" "ff3873fc"
  test "00000004/81020400" "fffffff0"
  test "111028b0/40021100" "e08fd744"
  test "6808490c/01959000" "17f7b650"
  test "30821004/81014040" "c75de5f8"
  test "0004c810/10003100" "fe4937c4"
  test "12022020/88200000" "edf08208"
  test "2aa92098/01160000" "45165964"
  test "00242940/10010004" "fc43c43c"
  test "483c2120/11004c00" "33c3de10"
  test "10140140/44004a04" "eda3fe3c"
  test "0c901d38/72602200" "f36da280"
  0