17 lines
432 B
Elixir
17 lines
432 B
Elixir
defmodule One do
|
|
def part1(list, initial_freq \\ 0), do: initial_freq + Enum.sum(list)
|
|
|
|
def part2(list, initial_freq \\ 0) do
|
|
list
|
|
|> Stream.cycle()
|
|
|> Enum.reduce_while({initial_freq, MapSet.new([initial_freq])}, &part2_reducer/2)
|
|
end
|
|
|
|
def part2_reducer(i, {last, set}) do
|
|
case (i + last) in set do
|
|
true -> {:halt, i + last}
|
|
_ -> {:cont, {i + last, MapSet.put(set, i + last)}}
|
|
end
|
|
end
|
|
end
|