Submission #17143240

---

Source Code Expand

defmodule Main do
  def main do
    [x, n] =
      IO.read(:line) |> String.trim() |> String.split(" ") |> Enum.map(&String.to_integer/1)

    if n > 0 do
      IO.read(:line)
      |> String.trim()
      |> String.split(" ")
      |> Enum.map(&String.to_integer/1)
      |> solve(x)
      |> IO.puts()
    else
      IO.read(:line)

      solve([], x)
      |> IO.puts()
    end
  end

  @doc ~S"""
  https://atcoder.jp/contests/abc170/tasks/abc170_c

  ## Examples

      iex> Abc170C.solve([4, 7, 10, 6, 5], 6)
      8
      iex> Abc170C.solve([4, 7, 10, 6, 5], 10)
      9
      iex> Abc170C.solve([], 100)
      100

  """
  def solve([], x), do: x

  def solve(list, x) do
    0..100
    |> Enum.reduce_while(x, fn i, acc ->
      minus_one = x - i

      if !(minus_one in list) do
        {:halt, minus_one}
      else
        plus_one = x + i

        if !(plus_one in list) do
          {:halt, plus_one}
        else
          {:cont, acc}
        end
      end
    end)
  end
end

Submission Info

Judge Result