refactor day 13 to use modules

elixir/livebook/2024/day13.livemd

@@ -14,7 +14,12 @@ input = """
 ```
 
 ```elixir
-for {a, b} <- (for line <- (input |> String.trim() |> String.split("\n")), reduce: {[], []} do
+defmodule ClawContraption do
+  def part1(input), do: parse(input, 0) |> solve()
+  def part2(input), do: parse(input, 10000000000000) |> solve()
+  
+  def parse(input, n) do
+    (for line <- (input |> String.trim() |> String.split("\n")), reduce: {[], []} do
       {vecs, matrices} = acc -> 
        case line do
          "Button " <> rest ->
@@ -25,11 +30,15 @@ for {a, b} <- (for line <- (input |> String.trim() |> String.split("\n")), reduc
            [[_, a, b]] = Regex.scan(~r/X=(\d+), Y=(\d+)/, rest)
            v = [a, b] |> Enum.map(&String.to_integer(&1))
            a = Nx.tensor(vecs, type: :f64) |> Nx.transpose()
-       b = Nx.tensor(v |> Enum.map(&(&1+10000000000000)), type: :f64)
+           b = Nx.tensor(v |> Enum.map(&(&1+n)), type: :f64)
            {[], [{a, b} | matrices]}
          _ -> acc
        end
-    end |> elem(1)),
+        end |> elem(1))
+  end
+  
+  def solve(systems) do
+    for {a, b} <- systems,
         c = Nx.LinAlg.invert(a) |> Nx.dot(b)  |> Nx.round(),
         b_prime = Nx.dot(
             a, c
@@ -41,4 +50,15 @@ for {a, b} <- (for line <- (input |> String.trim() |> String.split("\n")), reduc
         acc2 ->
           c |> Nx.dot(Nx.tensor([1, 3], type: :s64)) |> Nx.add(acc2)
       end 
+  end
+end
+
+```
+
+```elixir
+ClawContraption.part1(input)
+```
+
+```elixir
+ClawContraption.part2(input)
 ```