ABC086C - Traveling

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
    points =
      input
      |> split_lines()
      |> tl()
      |> Enum.map(fn line ->
        line
        |> split_words()
        |> Enum.map(&String.to_integer/1)
      end)

    [[0, 0, 0] | Enum.drop(points, -1)]
    |> Enum.zip(points)
    |> Enum.all?(fn {[pre_t, pre_x, pre_y], [post_t, post_x, post_y]} ->
      inc_t = post_t - pre_t
      inc_d = abs(post_x - pre_x) + abs(post_y - pre_y)
      margin = inc_t - inc_d

      margin >= 0 && rem(margin, 2) == 0
    end)
    |> if(do: "Yes", else: "No")
  end
end

"""
2
3 1 2
6 1 1
"""
|> Main.solve()
|> then(&(&1 == "Yes"))

"""
1
2 100 100
"""
|> Main.solve()
|> then(&(&1 == "No"))

"""
2
5 1 1
100 1 1
"""
|> Main.solve()
|> then(&(&1 == "No"))