Day 2 Challenge Advent of Code

Day_02.ex

lines = File.read!("./input.txt") |> String.trim() |> String.split("\n")

defmodule Day2 do
  def count_occurrences(line) do
    String.split(line, "")
    |> Enum.filter(fn x -> x != "" end)
    |> group_and_count()
    |> Enum.uniq()
  end

  def group_and_count(list) do
    list
    |> Enum.group_by(fn x -> x end)
    |> Enum.filter(fn {k, v} -> Enum.count(v) > 1 end)
    |> Enum.map(fn {char, occurrences} -> Enum.count(occurrences) end)
  end
end

lines
|> Enum.map(&Day2.count_occurrences/1)
|> Enum.concat()
|> Day2.group_and_count()
|> Enum.reduce(fn v, acc -> acc * v end)
|> IO.inspect()