https://paiza.jp/poh/joshibato

joshibato.erl

-module(main).
-export([main/0, main/1]).

main() ->
  main([""]).

main([_]) ->
  {N, Nv, M} = read_line(),

  Parent = self(),
  Pids = lists:map(fun(Mj) ->
                    spawn_link(fun() ->
                                 Msg = case Mj+1 > N of
                                   true ->
                                     "No";
                                   _ ->
                                     Move = lists:nth(Mj+1, Nv),
                                     go2goal(N, Nv, Mj+Move, Move)
                                 end,
                                 Parent ! {self(), Msg}
                               end)
                end, M),
  do_receive(Pids),
  init:stop().

do_receive([])      -> ok;
do_receive([Pid|T]) ->
  receive
    {Pid, Msg} ->
      io:format("~s~n", [Msg]),
      do_receive(T)
  end.

go2goal(N, _Nv, Mj, _Moved)  when N == Mj+1  -> "Yes";
go2goal(N, _Nv, Mj, _Moved)  when N < Mj     -> "No";
go2goal(_N, _Nv, _Mj, Moved) when Moved == 0 -> "No";
go2goal(N, Nv, Mj, Moved) ->
  Move = lists:nth(Mj+1, Nv),
  case Move + Moved of
    0 -> "No";
    _ -> go2goal(N, Nv, Mj+Move, Move)
  end.

%%
%% Read from stdin.
%%
read_line() ->
  N   = list_to_integer(trim_whitespace(io:get_line(""))),
  Nv  = nv_split(trim_whitespace(io:get_line(""))),
  M   = list_to_integer(trim_whitespace(io:get_line(""))),
  Acc = read_line([], M),
  {N, Nv, Acc}.

read_line(Acc, 0) ->
  lists:reverse(Acc);
read_line(Acc, N) ->
  Input = list_to_integer(trim_whitespace(io:get_line(""))),
  read_line([Input|Acc], N-1).

trim_whitespace(Input) ->
  [D, []] = re:replace(Input, "\\n$", "", [global]),
  binary_to_list(D).

nv_split(List) ->
  Splited = binary:split(list_to_binary(List), <<" ">>, [global]),
  lists:map(fun(X) -> list_to_integer(binary_to_list(X)) end, Splited).