Classify 2018 solutions

Author: code-shoily

lib/2018/day_01.ex

@@ -2,6 +2,8 @@ defmodule AdventOfCode.Y2018.Day01 do
   @moduledoc """
   --- Day 1: Chronal Calibration ---
   Problem Link: https://adventofcode.com/2018/day/1
+  Difficulty: s
+  Tags: sequence set
   """
   alias AdventOfCode.Helpers.{InputReader, Transformers}
 

lib/2018/day_02.ex

@@ -2,6 +2,8 @@ defmodule AdventOfCode.Y2018.Day02 do
   @moduledoc """
   --- Day 2: Inventory Management System ---
   Problem Link: https://adventofcode.com/2018/day/2
+  Difficulty: s
+  Tags: checksum string-result set
   """
   alias AdventOfCode.Helpers.{InputReader, Transformers}
 

lib/2018/day_03.ex

@@ -2,6 +2,8 @@ defmodule AdventOfCode.Y2018.Day03 do
   @moduledoc """
   --- Day 3: No Matter How You Slice It ---
   Problem Link: https://adventofcode.com/2018/day/3
+  Difficulty: m
+  Tags: grid set not-fast-enough
   """
   alias AdventOfCode.Helpers.{InputReader, Transformers}
 
@@ -27,7 +29,7 @@ defmodule AdventOfCode.Y2018.Day03 do
     |> elem(0)
   end
 
-  def parse(input) do
+  def parse(input \\ input()) do
     input
     |> Transformers.lines()
     |> Stream.map(&parse_line/1)

lib/2018/day_04.ex

@@ -2,6 +2,8 @@ defmodule AdventOfCode.Y2018.Day04 do
   @moduledoc """
   --- Day 4: Repose Record ---
   Problem Link: https://adventofcode.com/2018/day/4
+  Difficulty: s
+  Tags: date-time sequence sort map
   """
   alias AdventOfCode.Helpers.{InputReader, Transformers}
 

lib/2018/day_05.ex

@@ -2,9 +2,8 @@ defmodule AdventOfCode.Y2018.Day05 do
   @moduledoc """
   --- Day 5: Alchemical Reduction ---
   Problem Link: https://adventofcode.com/2018/day/5
-
-  Thanks to `BenAlbin/Adent-Of-Code-2018` for the fastest solution, and helping me
-  learn interesting way of solving the problem.
+  Difficulty: l
+  Tags: reduction simulation
   """
   alias AdventOfCode.Helpers.InputReader
 

lib/2018/day_06.ex

@@ -2,6 +2,8 @@ defmodule AdventOfCode.Y2018.Day06 do
   @moduledoc """
   --- Day 6: Chronal Coordinates ---
   Problem Link: https://adventofcode.com/2018/day/6
+  Difficulty: s
+  Tags: not-fast-enough grid distance bounded-box
   """
   @type point :: {integer(), integer()}
   @type points :: list(point())
@@ -19,7 +21,7 @@ defmodule AdventOfCode.Y2018.Day06 do
   end
 
   @spec parse(binary()) :: points()
-  def parse(data) do
+  def parse(data \\ input()) do
     data
     |> Transformers.lines()
     |> Enum.map(fn line ->

lib/2018/day_08.ex

@@ -2,6 +2,8 @@ defmodule AdventOfCode.Y2018.Day08 do
   @moduledoc """
   --- Day 8: Memory Maneuver ---
   Problem Link: https://adventofcode.com/2018/day/8
+  Difficulty: l
+  Tags: sequence walk
   """
   alias AdventOfCode.Helpers.{InputReader, Transformers}
 
@@ -13,7 +15,7 @@ defmodule AdventOfCode.Y2018.Day08 do
     {metadata_sum(input), nil}
   end
 
-  def parse(data), do: Enum.map(Transformers.words(data), &String.to_integer/1)
+  def parse(data \\ input()), do: Enum.map(Transformers.words(data), &String.to_integer/1)
   def metadata_sum(lst), do: walk(lst, [], [], []) |> Enum.flat_map(& &1) |> Enum.sum()
   def walk([], _, _, metadata), do: metadata
 

lib/2018/day_09.ex

@@ -2,6 +2,8 @@ defmodule AdventOfCode.Y2018.Day09 do
   @moduledoc """
   --- Day 9: Marble Mania ---
   Problem Link: https://adventofcode.com/2018/day/9
+  Difficulty: s
+  Tags: not-fast-enough circular-linked-list
   """
   alias AdventOfCode.Algorithms.BiCircularList