Format

lib/day1/day1.ex

@@ -11,6 +11,7 @@ defmodule Day1 do
     cond do
       Enum.member?(seen, sum) ->
         sum
+
       true ->
         first_repetition(shifts, next_index, sum, [sum | seen])
     end
@@ -21,6 +22,7 @@ defmodule Day1 do
     |> Stream.cycle()
     |> Enum.reduce_while({0, [0]}, fn shift, {sum, seen} ->
       sum = sum + shift
+
       cond do
         Enum.member?(seen, sum) -> {:halt, sum}
         true -> {:cont, {sum, [sum | seen]}}
@@ -33,6 +35,7 @@ defmodule Day1 do
     |> Stream.cycle()
     |> Enum.reduce_while({0, MapSet.new([0])}, fn shift, {sum, seen} ->
       sum = sum + shift
+
       cond do
         sum in seen -> {:halt, sum}
         true -> {:cont, {sum, MapSet.put(seen, sum)}}

lib/day2/day2.ex

@@ -25,11 +25,13 @@ defmodule Day2 do
   def diff(a, b) do
     a = String.graphemes(a)
     b = String.graphemes(b)
+
     Enum.zip(a, b)
     |> Enum.reduce({0, ""}, fn {a, b}, {diff_count, common} ->
       cond do
         a == b ->
           {diff_count, common <> a}
+
         true ->
           {diff_count + 1, common}
       end

lib/day3/day3.ex

@@ -1,11 +1,12 @@
 defmodule Day3 do
-  
   defmodule Rect do
     defstruct [:id, :left, :top, :width, :height]
 
     def points(nil), do: []
+
     def points(rect) do
       xs = rect.left..(rect.left + rect.width - 1)
+
       Enum.flat_map(xs, fn x ->
         ys = rect.top..(rect.top + rect.height - 1)
         Enum.map(ys, fn y -> {x, y} end)
@@ -17,23 +18,31 @@ defmodule Day3 do
       overlap_width = max(0, min(a.left + a.width, b.left + b.width) - overlap_left)
       overlap_top = max(a.top, b.top)
       overlap_height = max(0, min(a.top + a.height, b.top + b.height) - overlap_top)
+
       case overlap_width * overlap_height do
         0 ->
           nil
+
         _ ->
-          %Rect{left: overlap_left, top: overlap_top, width: overlap_width, height: overlap_height}
+          %Rect{
+            left: overlap_left,
+            top: overlap_top,
+            width: overlap_width,
+            height: overlap_height
+          }
       end
     end
   end
 
   def parse_rect(str) do
     parts = Regex.run(~r/#(\d+) @ (\d+),(\d+): (\d+)x(\d+)/, str)
+
     %Rect{
-      id: parts |> Enum.at(1) |> String.to_integer,
-      left: parts |> Enum.at(2) |> String.to_integer,
-      top: parts |> Enum.at(3) |> String.to_integer,
-      width: parts |> Enum.at(4) |> String.to_integer,
-      height: parts |> Enum.at(5) |> String.to_integer,
+      id: parts |> Enum.at(1) |> String.to_integer(),
+      left: parts |> Enum.at(2) |> String.to_integer(),
+      top: parts |> Enum.at(3) |> String.to_integer(),
+      width: parts |> Enum.at(4) |> String.to_integer(),
+      height: parts |> Enum.at(5) |> String.to_integer()
     }
   end
 
@@ -51,8 +60,8 @@ defmodule Day3 do
       end)
       |> Enum.flat_map(&Rect.points/1)
     end)
-      |> Enum.uniq
-      |> Enum.count
+    |> Enum.uniq()
+    |> Enum.count()
   end
 
   def exclude_overlapping(rects) do
@@ -82,5 +91,4 @@ defmodule Day3 do
     |> Enum.map(&parse_rect/1)
     |> exclude_overlapping()
   end
-
 end

test/day2_test.exs

@@ -3,7 +3,15 @@ defmodule Day2Test do
   doctest Day2
 
   test "count characters" do
-    assert Day2.count_characters("abcdef") == %{"a" => 1, "b" => 1, "c" => 1, "d" => 1, "e" => 1, "f" => 1}
+    assert Day2.count_characters("abcdef") == %{
+             "a" => 1,
+             "b" => 1,
+             "c" => 1,
+             "d" => 1,
+             "e" => 1,
+             "f" => 1
+           }
+
     assert Day2.count_characters("bababc") == %{"a" => 2, "b" => 3, "c" => 1}
     assert Day2.count_characters("abbcde") == %{"a" => 1, "b" => 2, "c" => 1, "d" => 1, "e" => 1}
   end

test/day3_test.exs

@@ -25,6 +25,7 @@ defmodule Day3Test do
       %Rect{id: 2, left: 3, top: 1, width: 4, height: 4},
       %Rect{id: 3, left: 5, top: 5, width: 2, height: 2}
     ]
+
     assert Day3.overlap_area(rects) == 4
   end
 
@@ -34,9 +35,9 @@ defmodule Day3Test do
       %Rect{id: 2, left: 3, top: 1, width: 4, height: 4},
       %Rect{id: 3, left: 5, top: 5, width: 2, height: 2}
     ]
+
     res = Day3.exclude_overlapping(rects)
     assert Enum.count(res) == 1
     assert Enum.at(res, 0).id == 3
   end
-  
 end