Day07 and Day08 both parts

lib/aoc2024/day_07.ex

@@ -1,13 +1,65 @@
 defmodule Aoc2024.Day07 do
   def parse(input) do
-    input |> String.split("\n", trim: true)
+    input 
+      |> String.split("\n", trim: true)
+      |> Enum.map(fn x -> x |> String.split(": ") |> Enum.into([]) end)
+      |> Enum.map(fn [x, y] -> {String.to_integer(x), y |> String.split(" ") |> Enum.map(&String.to_integer/1)} end)
+      |> Enum.into([])
   end
 
-  def part1(_lines) do
-    :todo1
+  def part1(input) do
+    input
+      |> Enum.map(fn {target, numbers} -> Task.async(fn -> compute(target, numbers) end) end)
+      |> Enum.map(&Task.await/1)
+      |> Enum.filter(&Kernel.is_integer/1)
+      |> Enum.sum()
   end
 
-  def part2(_lines) do
-    :todo2
+  defp compute(target, numbers), do: compute(target, Enum.reverse(numbers), target)
+  defp compute(_, _, current) when current < 0, do: nil
+  defp compute(target, [], 0), do: target
+  defp compute(_, _, 0), do: nil 
+  defp compute(_, [], _), do: nil 
+  defp compute(target, [x | numbers], current) do
+    if rem(current, x) == 0 do
+      if compute(target, numbers, div(current, x)) == target do
+        target
+      else 
+        compute(target, numbers, current - x)
+      end
+    else 
+      compute(target, numbers, current - x)
+    end
+  end
+
+    
+
+  def part2(input) do
+    input
+      |> Enum.map(fn {target, numbers} -> Task.async(fn -> compute2(target, numbers) end) end)
+      |> Enum.map(&Task.await/1)
+      |> Enum.filter(&Kernel.is_integer/1)
+      |> Enum.sum()
+  end
+
+  defp compute2(target, numbers), do: compute2(target, Enum.reverse(numbers), target)
+  defp compute2(_, _, current) when current < 0, do: nil
+  defp compute2(target, [], 0), do: target
+  defp compute2(_, _, 0), do: nil 
+  defp compute2(_, [], _), do: nil 
+  defp compute2(target, [x | numbers], current) do
+    s_c = current |> Integer.to_string()
+    s_x = x |> Integer.to_string()
+    nc = s_c |> String.replace_suffix(s_x, "") 
+    cond do
+      s_c |> String.ends_with?(s_x)
+        and nc != ""
+        and compute2(target, numbers, nc |> String.to_integer()) == target ->
+        target
+      rem(current, x) == 0 and compute2(target, numbers, div(current, x)) == target -> 
+        target
+      true -> 
+        compute2(target, numbers, current - x)
+    end
   end
 end