Finished day 2

day2.livemd

@@ -42,6 +42,23 @@ defmodule Util do
     end)
   end
 
+  def process2(input) do
+    input
+    |> String.split("\n", trim: true)
+    |> Enum.map(fn entry ->
+      entry
+      |> String.split()
+      |> Enum.map(fn
+        "A" -> :rock
+        "B" -> :paper
+        "C" -> :scissors
+        "X" -> :lose
+        "Y" -> :draw
+        "Z" -> :win
+      end)
+    end)
+  end
+
   # Check your opponent vs you
   def check_pair(:rock, :rock), do: :draw
   def check_pair(:rock, :paper), do: :win
@@ -53,6 +70,17 @@ defmodule Util do
   def check_pair(:scissors, :paper), do: :lose
   def check_pair(:scissors, :scissors), do: :draw
 
+  # Check reverse
+  def check_pair(:rock, :lose), do: :scissors
+  def check_pair(:rock, :draw), do: :rock
+  def check_pair(:rock, :win), do: :paper
+  def check_pair(:paper, :lose), do: :rock
+  def check_pair(:paper, :draw), do: :paper
+  def check_pair(:paper, :win), do: :scissors
+  def check_pair(:scissors, :lose), do: :paper
+  def check_pair(:scissors, :draw), do: :scissors
+  def check_pair(:scissors, :win), do: :rock
+
   def points(:win), do: 6
   def points(:draw), do: 3
   def points(:lose), do: 0
@@ -74,7 +102,10 @@ end
 
 defmodule Part2 do
   def run(input) do
-    0
+    Util.process2(input)
+    |> Enum.map(fn [they, you] -> {you, Util.check_pair(they, you)} end)
+    |> Enum.map(fn {played, result} -> Util.points(played) + Util.points(result) end)
+    |> Enum.sum()
   end
 end
 
@@ -104,7 +135,7 @@ C Z)
   end
 
   test "part 2" do
-    assert Part2.run(@input) === 0
+    assert Part2.run(@input) === 13693
   end
 end