From f35ba521e1b2e07580575395ce6968645e5df09e Mon Sep 17 00:00:00 2001
From: sloane <1699281+sloanelybutsurely@users.noreply.github.com>
Date: Mon, 4 Dec 2023 08:35:12 -0500
Subject: [PATCH] solve 2023 4.1

---
 2023/README.md            |  3 +-
 2023/elixir/lib/2023/4.ex | 62 +++++++++++++++++++++++++++++++++++++++
 README.md                 |  2 +-
 3 files changed, 65 insertions(+), 2 deletions(-)
 create mode 100644 2023/elixir/lib/2023/4.ex

diff --git a/2023/README.md b/2023/README.md
index 84b69c5..8e88a98 100644
--- a/2023/README.md
+++ b/2023/README.md
@@ -3,7 +3,7 @@
 |  S  |  M  |  T  |  W  |  T  |  F  |  S  |
 | :-: | :-: | :-: | :-: | :-: | :-: | :-: |
 |     |     |     |     |     | [1] | [2] |
-| [3] |  4  |  5  |  6  |  7  |  8  |  9  |
+| [3] | [4] |  5  |  6  |  7  |  8  |  9  |
 | 10  | 11  | 12  | 13  | 14  | 15  | 16  |
 | 17  | 18  | 19  | 20  | 21  | 22  | 23  |
 | 24  | 25  |     |     |     |     |     |
@@ -12,3 +12,4 @@
 [1]: ./elixir/lib/2023/1.ex
 [2]: ./elixir/lib/2023/2.ex
 [3]: ./elixir/lib/2023/3.ex
+[4]: ./elixir/lib/2023/4.ex
diff --git a/2023/elixir/lib/2023/4.ex b/2023/elixir/lib/2023/4.ex
new file mode 100644
index 0000000..360dbbf
--- /dev/null
+++ b/2023/elixir/lib/2023/4.ex
@@ -0,0 +1,62 @@
+import AOC
+
+aoc 2023, 4 do
+  def p1(input) do
+    input
+    |> String.split("\n")
+    |> Stream.map(&parse_line/1)
+    |> Stream.map(&score_1/1)
+    |> Enum.sum()
+  end
+
+  def p2(_input) do
+    # input
+    # |> String.split("\n")
+    # |> Enum.map(&parse_line/1)
+    # |> Enum.map(&score_2/1)
+  end
+
+  def parse_line(line) do
+    ["Card " <> card_string, numbers_string] = String.split(line, ": ")
+    [winning_string, you_have_string] = String.split(numbers_string, " | ")
+
+    card =
+      card_string
+      |> String.trim()
+      |> String.to_integer()
+
+    winning =
+      winning_string
+      |> String.split(" ", trim: true)
+      |> Enum.map(&String.to_integer/1)
+
+    you_have =
+      you_have_string
+      |> String.split(" ", trim: true)
+      |> Enum.map(&String.to_integer/1)
+
+    {card, winning, you_have}
+  end
+
+  def score_1({_, winning, you_have}) do
+    number_of_winners =
+      winning
+      |> Enum.filter(&Enum.member?(you_have, &1))
+      |> Enum.count()
+
+    if number_of_winners < 1 do
+      0
+    else
+      2 ** (number_of_winners - 1)
+    end
+  end
+
+  def score_2({id, winning, you_have}) do
+    number_of_winners =
+      winning
+      |> Enum.filter(&Enum.member?(you_have, &1))
+      |> Enum.count()
+
+    {id, number_of_winners}
+  end
+end
diff --git a/README.md b/README.md
index 8a4b0de..389032c 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@
 1. [2020] **17/50** 🌟
 1. [2021] **43/50** 🌟
 1. [2022] **14/50** 🌟
-1. [2023] **6/50** 🌟
+1. [2023] **7/50** 🌟
 
 [2015]: ./2015
 [2017]: ./2017