change directory names

22/lib/days/day11.ex

@@ -0,0 +1,93 @@
+defmodule AOC.Day11 do
+  use AOC.Day, day: 11
+  alias AOC.Day11.{MonkeyRegistry, Monkey}
+
+  def parse_input(lines) do
+    monkeys =
+      lines
+      |> Enum.chunk_by(&(&1 == ""))
+      |> Enum.reject(&(&1 == [""]))
+      |> Enum.map(&parse_monkey/1)
+
+    supermod =
+      monkeys
+      |> Enum.map(& &1.modulo)
+      |> Enum.reduce(&Kernel.*/2)
+
+    {:ok, _} = Registry.start_link(keys: :unique, name: MonkeyRegistry)
+
+    Enum.each(monkeys, fn %{id: id} = monkey ->
+      GenServer.start_link(Monkey, Map.put(monkey, :supermod, supermod),
+        name: {:via, Registry, {MonkeyRegistry, id}}
+      )
+    end)
+
+    Enum.count(monkeys)
+  end
+
+  def parse_monkey([
+        "Monkey " <> monkey_id,
+        "Starting items: " <> items,
+        "Operation: " <> operation,
+        "Test: divisible by " <> modulo,
+        "If true: throw to monkey " <> true_monkey_id,
+        "If false: throw to monkey " <> false_monkey_id
+      ]) do
+    %{
+      id: monkey_id |> String.slice(0..-2) |> String.to_integer(),
+      items: items |> String.split(", ") |> Enum.map(&String.to_integer/1),
+      operation: parse_operation(operation),
+      modulo: String.to_integer(modulo),
+      true_monkey_id: String.to_integer(true_monkey_id),
+      false_monkey_id: String.to_integer(false_monkey_id)
+    }
+  end
+
+  def parse_operation(operation) do
+    ["new", "=", lhs, op, rhs] = String.split(operation)
+
+    fn old ->
+      lhs = if lhs == "old", do: old, else: String.to_integer(lhs)
+      rhs = if rhs == "old", do: old, else: String.to_integer(rhs)
+
+      op =
+        case op do
+          "*" -> &Kernel.*/2
+          "+" -> &Kernel.+/2
+        end
+
+      op.(lhs, rhs)
+    end
+  end
+
+  def part1(monkey_count) do
+    # monkey_business(monkey_count, 20, false)
+  end
+
+  def part2(monkey_count) do
+    monkey_business(monkey_count, 10000, true)
+  end
+
+  def monkey_business(monkey_count, rounds, ridiculous) do
+    execute_rounds(monkey_count, rounds, ridiculous)
+
+    Enum.map(0..(monkey_count - 1), fn id ->
+      [{pid, _}] = Registry.lookup(MonkeyRegistry, id)
+      Monkey.get_activeness(pid)
+    end)
+    |> Enum.sort(:desc)
+    |> Enum.take(2)
+    |> Enum.reduce(&Kernel.*/2)
+  end
+
+  def execute_rounds(monkey_count, rounds, ridiculous) do
+    Enum.each(0..(rounds - 1), fn _ -> execute_round(monkey_count, ridiculous) end)
+  end
+
+  def execute_round(monkey_count, ridiculous) do
+    Enum.each(0..(monkey_count - 1), fn id ->
+      [{pid, _}] = Registry.lookup(MonkeyRegistry, id)
+      Monkey.execute_turn(pid, ridiculous)
+    end)
+  end
+end