ビットボンバーマンをErlangで(横へな8) ref: http://qiita.com/pazworld/items/73b8392c5972b8c7db2c

bitbomb.erl

-module(bitbomb).
-compile(export_all).

%% 問題を解く
solve(Data) ->
  {Wall, Bomb} = list_to_tuple([list_to_integer(X, 16)
    || X <- string:tokens(Data, "/")]),
  DirInfo = [ % シフト方向とシフト時マスクのデーター
    {-6, 2#00000011111111111111111111111100},  % 上
    {-1, 2#01111101111101111101111101111100},  % 左
    {+1, 2#11111011111011111011111011111000},  % 右
    {+6, 2#11111111111111111111111100000000}], % 下
  AllFlare = lists:foldl(fun(XDir, Acc) ->
      Acc bor flare(Wall, Bomb, XDir) end, 0, DirInfo),
  lists:flatten(io_lib:format("~8.16.0b", [AllFlare])).

%% 壁、爆弾、爆風方向から爆風の軌跡を返す
flare(Wall, Bomb, {Dir, DirMask}) ->
  WallMask = 16#FFFFFFFC - Wall,
  {_Flare, FlareTrail} = times(6, fun({Flare, FlareTrail}) ->
    WalledFlair = WallMask band Flare,
    NextFlair = (WalledFlair band DirMask) bsr Dir,
    {NextFlair, WalledFlair bor FlareTrail}
  end, {Bomb, 0}),
  FlareTrail.

%% 関数を指定回数繰り返す
times(0, _Fun, Acc) -> Acc;
times(N, Fun, Acc) -> times(N - 1, Fun, Fun(Acc)).

%% マップを表示する (デバッグ用)
show_map(X) ->
  Show = fun
    (_F, []) -> ok;
    (F, S) ->
      io:fwrite("~s~n", [string:left(S, 6)]),
      F(F, lists:nthtail(6, S))
  end,
  Show(Show, string:right(string:chars($0, 30)
    ++ integer_to_list(X div 4, 2), 30)).

test(Data, Expected) ->
  Result = solve(Data),
  OkNg = case Result =:= Expected of true -> ok; false -> ng end,
  io:fwrite("~s: ~s -> ~s~n", [OkNg, Data, Result]).

tests() ->
  test("802b1200/01400c20", "53c40cfc"), %0
  test("28301068/84080504", "d64fef94"), %1
  test("100a4010/80010004", "e241850c"), %2
  test("81020400/000000fc", "0e3cfbfc"), %3
  test("80225020/7e082080", "7fdd24d0"), %4
  test("01201200/40102008", "fe1861fc"), %5
  test("00201000/01000200", "43c48f08"), %6
  test("00891220/81020408", "ff060c1c"), %7
  test("410033c0/0c300000", "3cf0c000"), %8
  test("00000000/01400a00", "7bf7bf78"), %9
  test("00000000/20000a00", "fca2bf28"), %10
  test("00000000/00000000", "00000000"), %11
  test("00cafe00/00000000", "00000000"), %12
  test("aaabaaaa/50000000", "51441040"), %13
  test("a95a95a8/56a56a54", "56a56a54"), %14
  test("104fc820/80201010", "ea30345c"), %15
  test("4a940214/05000008", "05000008"), %16
  test("00908000/05000200", "ff043f48"), %17
  test("00c48c00/fe1861fc", "ff3873fc"), %18
  test("00000004/81020400", "fffffff0"), %19
  test("111028b0/40021100", "e08fd744"), %20
  test("6808490c/01959000", "17f7b650"), %21
  test("30821004/81014040", "c75de5f8"), %22
  test("0004c810/10003100", "fe4937c4"), %23
  test("12022020/88200000", "edf08208"), %24
  test("2aa92098/01160000", "45165964"), %25
  test("00242940/10010004", "fc43c43c"), %26
  test("483c2120/11004c00", "33c3de10"), %27
  test("10140140/44004a04", "eda3fe3c"), %28
  test("0c901d38/72602200", "f36da280"). %29