From 1f246c509ef6746c8f7ff4e34d5d18f07e7bc057 Mon Sep 17 00:00:00 2001
From: Adam Millerchip <adam@millerchip.net>
Date: Sat, 14 Dec 2024 00:04:52 +0900
Subject: [PATCH] 2024 Day 14 (just parsing input + notes, no solution)
---
2024/day14_wip.exs | 81 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 81 insertions(+)
create mode 100755 2024/day14_wip.exs
diff --git a/2024/day14_wip.exs b/2024/day14_wip.exs
new file mode 100755
index 0000000..aa61de6
--- /dev/null
+++ b/2024/day14_wip.exs
@@ -0,0 +1,81 @@
+#!/usr/bin/env elixir
+defmodule Day13 do
+ defmodule Machine do
+ defstruct [:a, :b, :prize]
+ end
+
+ def part1(input) do
+ input
+ # these are equivalent linear equations
+ # know how to do it algebraically, but not algorithmically
+ # e.g. for first example
+ #
+ # 94a + 22b - 8400 = 34a + 67b - 5400
+ # 94a + 22b - 3000 = 34a + 67b
+ # 60a + 22b - 3000 = 67b
+ # 60a - 3000 = 45b
+ # 4a - 200 = 3b
+ # a = 3/4b + 50
+ # 34(3/4b + 50) + 67b - 5400 = 0
+ # 25.5b + 1700 + 67b - 5400 = 0
+ # 92.5b = 3700
+ # b = 40
+ # 34a + 67(40) = 5400
+ # 34a + 2680 = 5400
+ # 34a = 2720
+ # a = 80
+ end
+
+ def part2(_input) do
+ :ok
+ end
+
+ def input do
+ with [input_filename] <- System.argv(),
+ {:ok, input} <- File.read(input_filename) do
+ input
+ |> String.split("\n\n")
+ |> Enum.map(fn machine ->
+ machine
+ |> String.split(["+", ",", "=", "\n"], trim: true)
+ |> tl()
+ |> Enum.take_every(2)
+ |> Enum.map(&String.to_integer/1)
+ end)
+ else
+ _ -> :error
+ end
+ end
+
+ #######################
+ # HERE BE BOILERPLATE #
+ #######################
+
+ def run do
+ case input() do
+ :error -> print_usage()
+ input -> run_parts_with_timer(input)
+ end
+ end
+
+ defp run_parts_with_timer(input) do
+ run_with_timer(1, fn -> part1(input) end)
+ run_with_timer(2, fn -> part2(input) end)
+ end
+
+ defp run_with_timer(part, fun) do
+ {time, result} = :timer.tc(fun)
+ IO.puts("Part #{part} (completed in #{format_time(time)}):\n")
+ IO.puts("#{inspect(result)}\n")
+ end
+
+ defp format_time(μsec) when μsec < 1_000, do: "#{μsec}μs"
+ defp format_time(μsec) when μsec < 1_000_000, do: "#{μsec / 1000}ms"
+ defp format_time(μsec), do: "#{μsec / 1_000_000}s"
+
+ defp print_usage do
+ IO.puts("Usage: elixir day13.exs input_filename")
+ end
+end
+
+# Day13.run()