Day 6

lib/day6/day6.ex

@@ -41,10 +41,11 @@ defmodule Day6 do
     str
     |> String.replace(~r/\s/, "")
     |> String.to_charlist()
-    |> Enum.into(MapSet.new())
+    |> MapSet.new()
   end
 
   def questions_with_all_yes(str) do
+    people =
       str
       |> String.split("\n")
       |> Enum.map(fn person ->
@@ -52,14 +53,9 @@ defmodule Day6 do
         |> String.to_charlist()
         |> MapSet.new()
       end)
-    |> Enum.reduce(nil, fn person, acc ->
-      case acc do
-        nil ->
-          person
 
-        _ ->
-          MapSet.intersection(acc, person)
-      end
-    end)
+    people
+    |> Enum.drop(1)
+    |> Enum.reduce(List.first(people), &MapSet.intersection/2)
   end
 end