solve 2022 day 7 pt 1

2022/README.md

@@ -3,7 +3,7 @@
 |  S  |  M  |  T  |  W  |  T  |  F  |  S   |
 | :-: | :-: | :-: | :-: | :-: | :-: | :--: |
 |     |     |     |     | [1] | [2] |  [3] |
-| [4] | [5] | [6] |  7  |  8  |  9  |  10  |
+| [4] | [5] | [6] | [7] |  8  |  9  |  10  |
 | 11  | 12  | 13  | 14  | 15  | 16  |  17  |
 | 18  | 19  | 20  | 21  | 22  | 23  |  24  |
 | 24  |     |     |     |     |     |      |
@@ -14,3 +14,4 @@
 [4]: ./haskell/src/Aoc/Day4.hs
 [5]: ./haskell/src/Aoc/Day5.hs
 [6]: ./haskell/src/Aoc/Day6.hs
+[7]: ./elixir/lib/2022/7.ex

2022/elixir/lib/2022/7.ex

@@ -0,0 +1,50 @@
+import AOC
+
+aoc 2022, 7 do
+  def p1(input) do
+    {sized_dirs, _} = input
+    |> String.split("\n")
+    |> Enum.flat_map(&transform_input_line/1)
+    |> Enum.reduce({nil, %{}}, &update_state/2)
+    |> then(fn {_, fs} -> fs end)
+    |> calculate_dir_size("/")
+
+    sized_dirs
+    |> Enum.map(&elem(&1, 1))
+    |> Enum.reject(& &1 > 100_000)
+    |> Enum.sum()
+  end
+
+  def p2(_input) do
+  end
+
+  defp transform_input_line("$ cd " <> path), do: [{:cd, path}]
+  defp transform_input_line("$ ls" <> _), do: []
+  defp transform_input_line("dir " <> d), do: [{:d, d}]
+  defp transform_input_line(file) do
+    [size_s, f] = String.split(file, " ")
+    [{:f, f, String.to_integer(size_s)}]
+  end
+
+  defp update_state({:cd, path}, {cwd, fs}), do: {cd(cwd, path), fs}
+  defp update_state({:d, d}, {cwd, fs}), do: {cwd, Map.update(fs, cwd, [Path.join(cwd, d)], & [Path.join(cwd, d) | &1])}
+  defp update_state({:f, _, f}, {cwd, fs}), do: {cwd, Map.update(fs, cwd, [f], & [f | &1])}
+  defp update_state(_, s), do: s
+
+  defp cd(_cwd, "/" <> _ = path), do: path
+  defp cd(cwd, path), do: Path.join(cwd, path) |> Path.expand()
+
+  defp calculate_dir_size(fs, path) do
+    {updated_fs, total} = for item <- fs[path], reduce: {fs, 0} do
+      {acc_fs, sum} ->
+        case item do
+          f when is_integer(f) -> {acc_fs, sum + f}
+          d when is_binary(d) -> 
+            {acc_fs_, v} = calculate_dir_size(acc_fs, d)
+            {acc_fs_, v + sum}
+        end
+    end
+    {Map.put(updated_fs, path, total), total}
+  end
+
+end

README.md

@@ -13,7 +13,7 @@
 1. 2019
 1. [2020] **17/50** 🌟
 1. [2021] **43/50** 🌟
-1. [2022] **12/50** 🌟
+1. [2022] **13/50** 🌟
 
 [2015]: ./2015
 [2017]: ./2017