ABC130B - Bounding

問題

https://atcoder.jp/contests/abc130/tasks/abc130_b

回答2

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, x], l] =
      input
      |> split_lines()
      |> Enum.map(fn str ->
        str
        |> split_words()
        |> Enum.map(&String.to_integer/1)
      end)

    0..(n - 1)
    |> Stream.filter(fn d ->
      l
      |> Enum.slice(0..d)
      |> Enum.sum()
      |> Kernel.<=(x)
    end)
    |> Enum.count()
    |> Kernel.+(1)
  end
end

"""
3 6
3 4 5
"""
|> Main.solve()
|> then(&(&1 == 2))

"""
4 9
3 3 3 3
"""
|> Main.solve()
|> then(&(&1 == 4))