day 6

lib/advent_of_code/day_06.ex

@@ -1,7 +1,9 @@
 defmodule AdventOfCode.Day06 do
-  def part1(_args) do
+  def part1(inp) do
+    Advent.Code6_1.execute(inp)
   end
 
-  def part2(_args) do
+  def part2(inp) do
+    Advent.Code6_1.execute(inp)
   end
 end

lib/code/day6_1.ex

@@ -0,0 +1,34 @@
+defmodule Advent.Code6_1 do
+  @sep "\n"
+  defp parse_input(inp, sep) do
+    [time, distance] =
+      String.split(inp, sep, trim: true)
+      |> Enum.map(fn el -> String.split(el, ~r/[(Time:)(Distance:)]/) end)
+      |> Enum.map(fn sublist -> Enum.filter(sublist, fn el -> String.length(el) != 0 end) end)
+      |> Enum.map(fn sublist ->
+        Enum.map(sublist, fn el -> String.split(el, " ", trim: true) end)
+      end)
+      |> Enum.flat_map(fn el -> el end)
+      |> Enum.map(fn sublist ->
+        Enum.map(sublist, fn el -> My.Utils.string_to_num_or_false(el) end) |> Enum.with_index()
+      end)
+
+    time
+    |> Enum.map(fn {t_el, idx} ->
+      {d_el, idx} = Enum.at(distance, idx)
+      %{time: t_el, distance: d_el, idx: idx}
+    end)
+  end
+
+  defp calculate(row) do
+    Enum.to_list(0..row[:time])
+    |> Enum.filter(fn el -> el * (row[:time] - el) > row[:distance] end)
+    |> Enum.count()
+  end
+
+  def execute(inp) do
+    parse_input(inp, @sep)
+    |> Enum.map(fn el -> calculate(el) end)
+    |> Enum.reduce(fn el, acc -> acc * el end)
+  end
+end

test/advent_of_code/day_06_test.exs

@@ -3,19 +3,29 @@ defmodule AdventOfCode.Day06Test do
 
   import AdventOfCode.Day06
 
-  @tag :skip
+  def test_input1(),
+    do: """
+    Time:      7  15   30
+    Distance:  9  40  200
+    """
+
   test "part1" do
-    input = nil
+    input = test_input1()
     result = part1(input)
 
-    assert result
+    assert result == 288
   end
 
-  @tag :skip
+  def test_input2(),
+    do: """
+    Time:      71530
+    Distance:  940200
+    """
+
   test "part2" do
-    input = nil
+    input = test_input2()
     result = part2(input)
 
-    assert result
+    assert result == 71503
   end
 end