From 3e4e1dfd4a257fd36d093cc8426ae70c01e2ca7f Mon Sep 17 00:00:00 2001
From: sloane <git@sloanelybutsurely.com>
Date: Thu, 19 Dec 2024 13:53:10 -0500
Subject: [PATCH] (wip) 2024 day 14
---
2024/lib/2024/14.ex | 62 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
create mode 100644 2024/lib/2024/14.ex
diff --git a/2024/lib/2024/14.ex b/2024/lib/2024/14.ex
new file mode 100644
index 0000000..d043736
--- /dev/null
+++ b/2024/lib/2024/14.ex
@@ -0,0 +1,62 @@
+import AOC
+
+aoc 2024, 14 do
+ @example_bounds
+ # @bounds @example_bounds
+ # @real_bounds {101, 103}
+
+ def p1(input) do
+ robots =
+ input
+ |> read_robots()
+ |> Stream.iterate(fn robots ->
+ Enum.map(robots, &move_robot(&1, @bounds))
+ end)
+ |> Enum.at(100)
+ |> Enum.frequencies_by(&elem(&1, 0))
+
+ render(robots, @bounds)
+
+ :ok
+ end
+
+ def p2(_input) do
+ end
+
+ defp move_robot({{x, y}, {vx, vy} = velocity}, {max_x, max_y}) do
+ x_next = wrap_value(x + vx, max_x)
+ y_next = wrap_value(y + vy, max_y)
+
+ {{x_next, y_next}, velocity}
+ end
+
+ defp wrap_value(v, max) do
+ if v < 0 do
+ max + v
+ else
+ rem(v, max)
+ end
+ end
+
+ defp render(robots, {max_x, max_y}) do
+ for y <- 0..max_y do
+ line =
+ for x <- 0..max_x, into: "" do
+ "#{Map.get(robots, {x, y}, ".")}"
+ end
+
+ IO.puts(line)
+ end
+ end
+
+ ## input
+
+ defp read_robots(input) do
+ ~r/p=(\d+),(\d+) v=(-?\d+),(-?\d+)/
+ |> Regex.scan(input, capture: :all_but_first)
+ |> Enum.map(fn nums ->
+ [px, py, vx, vy] = Enum.map(nums, &String.to_integer/1)
+ {{px, py}, {vx, vy}}
+ end)
+ end
+end