ABC134B - Golden Apple

問題

https://atcoder.jp/contests/abc134/tasks/abc134_b

回答

defmodule Main do
  def main do
    :stdio
    |> IO.read(:all)
    |> solve()
    |> IO.puts()
  end

  defp split_words(words) do
    String.split(words, " ")
  end

  def solve(input) do
    [n, d] =
      input
      |> String.trim()
      |> split_words()
      |> Enum.map(&String.to_integer/1)

    ceil(n / (d * 2 + 1))
  end
end

"""
6 2
"""
|> Main.solve()
|> then(&(&1 == 2))

"""
14 3
"""
|> Main.solve()
|> then(&(&1 == 2))

"""
20 4
"""
|> Main.solve()
|> then(&(&1 == 3))