aocday13

Mix.install([
  {:kino, "~> 0.14.2"}
])

Section

input = Kino.Input.textarea("Please paste your input file")  

claw_machines = Regex.scan(~r/-?\d+/, input |> Kino.Input.read()) 
  |> List.flatten()
  |> Enum.map(&String.to_integer/1)
  |> Enum.chunk_every(6)

claw_machines |> Enum.map(fn [a, c, b, d, e, f] ->

  x = round(((e * d) - (b * f)) / ((a * d) - (b * c)))
  y = round(((a * f) - (e * c)) / ((a * d) - (b * c)))

  if x * a + y * b == e && x * c + y * d == f do
    x * 3 + y
  else
    0
  end
  end) |> Enum.sum()

claw_machines |> Enum.map(fn [a, c, b, d, e, f] ->

  new_goal_1 = e + 10000000000000
  new_goal_2 = f + 10000000000000
  
  x = round(((new_goal_1 * d) - (b * new_goal_2)) / ((a * d) - (b * c)))
  y = round(((a * new_goal_2) - (new_goal_1 * c)) / ((a * d) - (b * c)))

  if x * a + y * b == new_goal_1 && x * c + y * d == new_goal_2 do
    x * 3 + y
  else
    0
  end
  end) |> Enum.sum()