From 67ff3997f15633864fbda9b3b851a6fd1be13fad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Anders=20Ytterstr=C3=B6m?= <yttan@fastmail.se>
Date: Tue, 6 Dec 2022 08:22:26 +0100
Subject: [PATCH] Add solutions for 2022:6 Tuning Trouble

---
 2022-elixir/lib/solutions/day_06.ex        | 43 +++++++++++++++++++++
 2022-elixir/test/solutions/day_06_test.exs | 45 ++++++++++++++++++++++
 2 files changed, 88 insertions(+)
 create mode 100644 2022-elixir/lib/solutions/day_06.ex
 create mode 100644 2022-elixir/test/solutions/day_06_test.exs

diff --git a/2022-elixir/lib/solutions/day_06.ex b/2022-elixir/lib/solutions/day_06.ex
new file mode 100644
index 0000000..6ce8710
--- /dev/null
+++ b/2022-elixir/lib/solutions/day_06.ex
@@ -0,0 +1,43 @@
+defmodule Aoc.Solution.Day06 do
+  @name "Day 6: Tuning Trouble"
+  @behaviour Solution
+
+  @impl Solution
+  def get_name, do: @name
+
+  @impl Solution
+  def present(solution), do: "Packet marker is at #{solution}"
+
+  @impl Solution
+  def present_again(solution), do: "Message marker is at #{solution}"
+
+  @impl Solution
+  def parse!(raw) do
+    raw |> String.trim() |> String.codepoints()
+  end
+
+  @impl Solution
+  def solve(datastream) do
+    datastream |> packet_marker()
+  end
+
+  @impl Solution
+  def solve_again(datastream) do
+    datastream |> message_marker()
+  end
+
+  def packet_marker(datastream) do
+    distinct_sequence(datastream, 4)
+  end
+
+  def message_marker(datastream) do
+    distinct_sequence(datastream, 14)
+  end
+
+  def distinct_sequence(datastream, l, start \\ 0) do
+    case datastream |> Enum.slice(start, l) |> MapSet.new() |> MapSet.size() do
+      ^l -> start + l
+      _ -> distinct_sequence(datastream, l, start + 1)
+    end
+  end
+end
diff --git a/2022-elixir/test/solutions/day_06_test.exs b/2022-elixir/test/solutions/day_06_test.exs
new file mode 100644
index 0000000..7760cec
--- /dev/null
+++ b/2022-elixir/test/solutions/day_06_test.exs
@@ -0,0 +1,45 @@
+defmodule Day06Test do
+  use ExUnit.Case
+  doctest Aoc.Solution.Day06
+  import Aoc.Solution.Day06
+
+  @input [
+    "mjqjpqmgbljsphdztnvjfqwrcgsmlb",
+    "bvwbjplbgvbhsrlpgdmjqwftvncz",
+    "nppdvjthqldpwncqszvftbrmjlhg",
+    "nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg",
+    "zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw"
+  ]
+
+  test "06: Tuning Trouble, part 1" do
+    [input_a, input_b, input_c, input_d, input_e] = @input
+
+    result_a = input_a |> parse!() |> solve()
+    result_b = input_b |> parse!() |> solve()
+    result_c = input_c |> parse!() |> solve()
+    result_d = input_d |> parse!() |> solve()
+    result_e = input_e |> parse!() |> solve()
+
+    assert result_a == 7
+    assert result_b == 5
+    assert result_c == 6
+    assert result_d == 10
+    assert result_e == 11
+  end
+
+  test "06: Tuning Trouble, part 2" do
+    [input_a, input_b, input_c, input_d, input_e] = @input
+
+    result_a = input_a |> parse!() |> solve_again()
+    result_b = input_b |> parse!() |> solve_again()
+    result_c = input_c |> parse!() |> solve_again()
+    result_d = input_d |> parse!() |> solve_again()
+    result_e = input_e |> parse!() |> solve_again()
+
+    assert result_a == 19
+    assert result_b == 23
+    assert result_c == 23
+    assert result_d == 29
+    assert result_e == 26
+  end
+end