Day 6

lib/day6/day6.ex

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