ABC088B - Card Game for Two

問題

回答1

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

  defp split_lines(lines) do
    lines
    |> String.trim()
    |> String.split("\n")
  end

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

  def solve(input) do
    input
    |> split_lines()
    |> Enum.at(1)
    |> split_words()
    |> Enum.map(&String.to_integer/1)
    |> Enum.sort(:desc)
    |> Enum.chunk_every(2)
    |> Enum.map(fn
      [a, b] -> a - b
      [a] -> a
    end)
    |> Enum.sum()
  end
end

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

"""
3
2 7 4
"""
|> Main.solve()
|> then(&(&1 == 5))

"""
4
20 18 2 18
"""
|> Main.solve()
|> then(&(&1 == 18))