refactor day 13 to use modules

elixir/livebook/2024/day13.livemd

@@ -14,31 +14,51 @@ input = """
 ```
 
 ```elixir
-for {a, b} <- (for line <- (input |> String.trim() |> String.split("\n")), reduce: {[], []} do
-  {vecs, matrices} = acc -> 
-   case line do
-     "Button " <> rest ->
-       [[_, a, b]] = Regex.scan(~r/[AB]: X\+(\d+), Y\+(\d+)/, rest)
-       v = [a, b] |> Enum.map(&String.to_integer(&1))
-       {[v | vecs], matrices}
-     "Prize: " <> rest ->
-       [[_, 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)
-       {[], [{a, b} | matrices]}
-     _ -> acc
-   end
-    end |> elem(1)),
-    c = Nx.LinAlg.invert(a) |> Nx.dot(b)  |> Nx.round(),
-    b_prime = Nx.dot(
-        a, c
-    ) |> Nx.round() |> Nx.as_type(:f64),
-  c = Nx.as_type(c, :s64),
-    b == b_prime,
-  reduce: Nx.tensor(0, type: :s64)
-  do
-    acc2 ->
-      c |> Nx.dot(Nx.tensor([1, 3], type: :s64)) |> Nx.add(acc2)
-  end 
+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 ->
+           [[_, a, b]] = Regex.scan(~r/[AB]: X\+(\d+), Y\+(\d+)/, rest)
+           v = [a, b] |> Enum.map(&String.to_integer(&1))
+           {[v | vecs], matrices}
+         "Prize: " <> rest ->
+           [[_, 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+n)), type: :f64)
+           {[], [{a, b} | matrices]}
+         _ -> acc
+       end
+        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
+        ) |> Nx.round() |> Nx.as_type(:f64),
+      c = Nx.as_type(c, :s64),
+        b == b_prime,
+      reduce: Nx.tensor(0, type: :s64)
+      do
+        acc2 ->
+          c |> Nx.dot(Nx.tensor([1, 3], type: :s64)) |> Nx.add(acc2)
+      end 
+  end
+end
+
+```
+
+```elixir
+ClawContraption.part1(input)
+```
+
+```elixir
+ClawContraption.part2(input)
 ```