ABC133B - Good Distance

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
    [[n, d] | x_list] =
      input
      |> split_lines()
      |> Enum.map(fn str ->
        str
        |> split_words()
        |> Enum.map(&String.to_integer/1)
      end)

    for i <- 0..(n - 2),
        j <- (i + 1)..(n - 1) do
      y = Enum.at(x_list, i)
      z = Enum.at(x_list, j)

      for k <- 0..(d - 1) do
        :math.pow(Enum.at(y, k) - Enum.at(z, k), 2)
      end
      |> Enum.sum()
      |> :math.sqrt()
    end
    |> Enum.count(&amp;(&amp;1 == ceil(&amp;1)))
  end
end

"""
3 2
1 2
5 5
-2 8
"""
|> Main.solve()
|> then(&(&1 == 1))

"""
3 4
-3 7 8 2
-12 1 10 2
-2 8 9 3
"""
|> Main.solve()
|> then(&(&1 == 2))

"""
5 1
1
2
3
4
5
"""
|> Main.solve()
|> then(&(&1 == 10))