Add simpler implementation for Day1

day1/README

@@ -32,3 +32,10 @@ E.g.
 
 However, can't short-circuit comprehensions, so maybe recursion was a good choice after all 🤷‍♂️
 
+Tried it out, and turned out that while it doesn't short-circuit, it's still pretty quick. So I added
+day1refactored.exs with the simpler implementation.
+
+$ elixir day1refactored.exs
+Part1: 618 x 1402 = 866436
+Part2: 928 x 547 x 545 = 276650720
+

day1/day1refactored.exs

@@ -0,0 +1,11 @@
+list =
+  File.read!("input")
+  |> String.trim()
+  |> String.split("\n")
+  |> Enum.map(&String.to_integer/1)
+
+[{a, b} | _] = for i <- list, j <- list, i + j == 2020, do: {i, j}
+IO.puts("Part1: #{a} x #{b} = #{a * b}")
+
+[{a, b, c} | _] = for i <- list, j <- list, k <- list, i + j + k == 2020, do: {i, j, k}
+IO.puts("Part2: #{a} x #{b} x #{c} = #{a * b * c}")