solve 2023 13.2

2023/lib/2023/13.ex

@@ -10,34 +10,40 @@ aoc 2023, 13 do
     |> Enum.sum()
   end
 
-  def p2(_input) do
+  def p2(input) do
+    input
+    |> String.split("\n\n")
+    |> Enum.map(&lines_of_chars/1)
+    |> Enum.map(&summarize(&1, 1))
+    |> Enum.sum()
   end
 
-  def summarize(lines) do
-    vertical_line_of_reflection = find_reflection_index(lines)
-    horizontal_line_of_reflection = lines |> transpose() |> find_reflection_index()
+  def summarize(lines, smudges \\ 0) do
+    vertical_line_of_reflection = find_reflection_index(lines, smudges)
+    horizontal_line_of_reflection = lines |> transpose() |> find_reflection_index(smudges)
 
     summary = vertical_line_of_reflection + 100 * horizontal_line_of_reflection
 
     summary
   end
 
-  def find_reflection_index(lines) do
+  def find_reflection_index(lines, smudges) do
     len = lines |> List.first() |> length()
 
     idx =
       for i <- 1..(len - 1) do
         lines
-        |> Enum.all?(fn line ->
+        |> Enum.map(fn line ->
           line
           |> Enum.split(i)
           |> Tuple.to_list()
           |> map_list([&Enum.reverse/1, &id/1])
           |> Enum.zip_with(&apply(Kernel, :==, &1))
-          |> Enum.all?(is?(true))
+          |> Enum.count(is?(false))
         end)
+        |> Enum.sum()
       end
-      |> Enum.find_index(is?(true))
+      |> Enum.find_index(is?(smudges))
 
     if idx, do: idx + 1, else: 0
   end

README.md

@@ -14,7 +14,7 @@
 1. [2020] **17/50** 🌟
 1. [2021] **43/50** 🌟
 1. [2022] **14/50** 🌟
-1. [2023] **18/50** 🌟
+1. [2023] **19/50** 🌟
 
 [2015]: ./2015
 [2017]: ./2017