Day Two

day1.exs

@@ -1,28 +1,28 @@
 defmodule DayOne do
-  def partOne(input) do
+  def part_one(input) do
     String.split(input, "\n")
           |> Enum.map(&DayOne.parseNum/1)
           |> List.foldr(0, &(&1 + &2))
   end
 
-  def partTwo(input), do: partTwo(String.split(input, "\n") |> Enum.map(&DayOne.parseNum/1), 0, [])
+  def part_two(input), do: partTwo(String.split(input, "\n") |> Enum.map(&DayOne.parseNum/1), 0, [])
 
-  def partTwo(input, acc , frequencies) do
+  def part_two(input, acc , frequencies) do
     [head | tail] = input
     freq = head + acc
     # IO.puts("Got frequency #{freq}")
     if Enum.member?(frequencies, freq), do: freq, else: partTwo(tail ++ [head], freq, [freq | frequencies])
   end
 
-  def parseNum("+" <> num) do 
+  def parse_num("+" <> num) do 
     {intVal, ""} = Integer.parse(num)
     intVal
   end
-  def parseNum("-" <> num) do
+  def parse_num("-" <> num) do
     {intVal, ""} = Integer.parse(num)
     0 - intVal
   end
-  def parseNum(num) do
+  def parse_num(num) do
     IO.puts(num)
     0
   end

day2.exs

@@ -0,0 +1,39 @@
+defmodule DayTwo do
+
+  def part_one(input) do
+    lines = String.split(input, "\n") |> Enum.map(&String.codepoints/1)
+    two = Enum.map(lines, fn string -> DayTwo.check_occurence(string, 2) end)
+      |> Enum.filter(&(&1))
+    three = Enum.map(lines, fn string -> DayTwo.check_occurence(string, 3) end)
+      |> Enum.filter(&(&1))
+    length(two) * length(three)
+  end
+
+  def check_occurence(line, req) do 
+    size = Enum.reduce(line, %{}, fn x, acc -> Map.update(acc, x, 1, &(&1 + 1)) end)
+        |> Enum.into([])
+        |> Enum.filter(fn {_, count} -> count == req end)
+        |> length
+    size > 0
+  end
+
+  def part_two(input) do
+    lines = String.split(input, "\n") |> Enum.map(&String.codepoints/1)
+    Enum.map(lines, fn line ->
+      Enum.map(lines, fn linetwo -> 
+        diff = compare_strings(line, linetwo)
+        if diff == 1 do
+          IO.puts("#{line} #{linetwo}")
+        end
+      end)
+    end)
+    nil
+  end
+
+  def compare_strings(one, two) do
+    Enum.zip(one, two)
+        |> Enum.filter(fn {one, two} -> one != two end)
+        |> length
+  end
+
+end