<!-- livebook:{"persist_outputs":true} -->

# Day 02

```elixir
Mix.install([
  {:kino_aoc, git: "https://github.com/ljgago/kino_aoc"}
])
```

<!-- livebook:{"output":true} -->

```
:ok
```

## Section

<!-- livebook:{"attrs":{"day":"2","session_secret":"ADVENT_OF_CODE_SESSION","variable":"puzzle_input","year":"2022"},"kind":"Elixir.KinoAOC.HelperCell","livebook_object":"smart_cell"} -->

```elixir
{:ok, puzzle_input} =
  KinoAOC.download_puzzle("2022", "2", System.fetch_env!("LB_ADVENT_OF_CODE_SESSION"))
```

<!-- livebook:{"output":true} -->

```
{:ok,
 "C Z\nC Y\nB X\nA Z\nC Z\nB X\nC Z\nB Z\nA Z\nA Z\nB Z\nB X\nC Z\nC Z\nA Z\nB Y\nB X\nC Y\nB X\nB X\nA Y\nA Z\nA Z\nA Z\nA Z\nC Z\nA Z\nC Z\nB X\nA X\nA Z\nB Y\nB X\nA Z\nB X\nC Z\nA Z\nC Z\nA Z\nA Z\nB X\nC X\nB X\nA X\nB X\nA Z\nA Z\nB X\nB Y\nB Y\nB Y\nC Z\nA Z\nA Z\nC X\nB X\nC Y\nB X\nC Z\nA Z\nC Z\nB X\nB X\nB Z\nB X\nA Z\nC Z\nA Z\nA Z\nA Z\nA Z\nB X\nC Z\nC Y\nA Z\nA Z\nA Z\nA Z\nC Z\nA X\nA Z\nA Z\nC Z\nC Y\nA Z\nC Y\nA Z\nA Z\nC Y\nC Z\nC Z\nA Z\nB Y\nB X\nB Y\nC Z\nA Z\nA Z\nA Z\nB Z\nC Z\nA Z\nB X\nC Y\nA Z\nB X\nA Z\nB Z\nA Z\nB X\nA Z\nB Y\nA Z\nA Z\nC Y\nA Z\nB Z\nA Z\nA Y\nB Y\nC Z\nA Z\nB X\nC Z\nC Z\nB X\nC Z\nC Z\nA Z\nB X\nC Z\nC Z\nA Z\nC Y\nA Z\nA Z\nB Y\nC Y\nA Z\nB X\nB Y\nB X\nB X\nA Z\nC Y\nA Z\nC Y\nA Z\nB Y\nC Z\nA Z\nA Z\nC Y\nA Z\nA Z\nC Z\nA Z\nA Z\nA Z\nC Y\nA Z\nB X\nC Z\nA Z\nC Z\nB Z\nC Z\nA Z\nC Y\nB X\nC Z\nC Z\nA Z\nC Y\nA Z\nB Y\nB X\nA Z\nC Y\nC Z\nB X\nC X\nB X\nC Y\nB X\nB X\nC Z\nB X\nA Z\nC X\nA Z\nC Z\nB X\nC Y\nA Z\nA Z\nC Z\nC Y\nA Z\nA Z\nA Z\nB X\nA Y\nB X\nC X\nC Z\nB X\nC Z\nC X\nA Z\nC Z\nB Z\nA X\nA Z\nC Y\nA Z\nC Z\nC Z\nB X\nC Z\nA X\nC Y\nC Z\nC Z\nC Z\nB Y\nC X\nB X\nA Z\nB Y\nA Z\nA Z\nC Y\nA Z\nB X\nA Y\nA Y\nC Y\nA Z\nA Z\nC Z\nA Z\nA Z\nA Z\nB Y\nB X\nB X\nA Z\nC X\nC Y\nA Z\nC Z\nA Z\nA Z\nA Z\nA Z\nA X\nA Z\nC Z\nA Z\nB Y\nA Y\nA Y\nC Y\nC Y\nB X\nB Y\nA Z\nA Z\nC X\nA Z\nB X\nC Y\nA Y\nA Y\nA Z\nC Y\nC Z\nB X\nA Z\nC Y\nB X\nC Z\nA Z\nB X\nA Z\nC Y\nB X\nC Z\nA Z\nA Z\nA Y\nA Z\nA Z\nC Y\nC Z\nA Z\nB X\nC Z\nC Y\nA Z\nA Z\nC Y\nA Z\nC Z\nB X\nA Z\nC Z\nA Z\nA Z\nA Z\nC Y\nC Y\nB X\nB Z\nB X\nA Z\nB Y\nB Y\nA Z\nA Z\nA Z\nB Y\nB Y\nC Y\nA Y\nA Z\nC X\nB X\nA Y\nB Y\nC Y\nA Z\nB Z\nC Y\nC Z\nB X\nA Z\nA X\nB X\nC Y\nB Z\nA Z\nB Y\nA Z\nB X\nA Z\nB X\nA Z\nC X\nC Y\nC Z\nB X\nC Z\nC Y\nA Z\nC X\nC Z\nA Z\nC Y\nA Y\nC Y\nC Y\nB Y\nA Z\nA Z\nA Y\nA Z\nC Z\nB X\nA Y\nB X\nB Y\nB X\nA Z\nC Z\nC Z\nC Y\nB X\nC Z\nA X\nA Z\nA Z\nA Y\nA Z\nA Z\nA Z\nA Z\nB Z\nB X\nB X\nC Y\nC Z\nC Z\nA Y\nB X\nC Z\nC X\nC Z\nB Y\nA Z\nB X\nB Y\nB X\nA Z\nB X\nB X\nA Z\nA Z\nC X\nB X\nC Z\nC X\nA Z\nA X\nC Z\nA Z\nA Z\nC Z\nB Z\nC Z\nB X\nA Z\nA Z\nC Z\nA Y\nA Z\nA Z\nC Y\nA Z\nB X\nB Y\nA Z\nA Y\nA X\nB X\nA Z\nA Z\nC Y\nC Y\nA Z\nC X\nA Z\nA Y\nA Z\nB Y\nA Z\nA Y\nB X\nC Z\nA Z\nB X\nA Z\nA Z\nB X\nA Z\nA Z\nB X\nA Z\nC Y\nA Z\nC Z\nC Y\nB Y\nB X\nA Z\nB Y\nA Z\nA Z\nB X\nA Z\nA Z\nB X\nC Z\nA Z\nC Z\nB X\nB X\nB Y\nA Y\nC Y\nB X\nA Z\nC Z\nA Z\nA Z\nA Z\nB X\nA Z\nB X\nA Z\nA Z\nA Z\nC Z\nA X\nB X\nB Z\nA Z\nA Z\nC Z\nA Z\nA Z\nA Z\nB Y\nA Y\nC Z\nB X\nB X\nC Y\nA Y\nA Z\nC X\nB Z\nA Z\nA Z\nC Z\nA Z\nA Y\nB Y\nC Z\nB X\nA Z\nA Z\nA Z\nC Z\nA Z\nA Y\nB X\nC Y\nA Z\nA Z\nA Z\nC X\nB X\nA Z\nA Z\nC Z\nB X\nA Z\nA Z\nA Z\nA Z\nA Z\nA Z\nC Y\nA Z\nB X\nA Y\nC Y\nA Z\nA Z\nB X\nA Z\nB Y\nA Y\nB X\nA X\nA Z\nC Z\nC Z\nC Y\nA Z\nB Y\nA Z\nC X\nA Z\nA Z\nB X\nA Z\nA Z\nB Y\nA Y\nA Z\nA Z\nB X\nC Y\nB X\nB Y\nC Y\nC X\nA Z\nA Z\nB Y\nA Z\nB Y\nC Y\nC Y\nA Z\nC Y\nA Z\nC Z\nA Z\nB X\nA Z\nA Z\nA X\nA Z\nA Z\nA Z\nA Z\nB Z\nC X\nB Y\nA Z\nC Z\nA Z\nA Z\nA Z\nC Z\nB X\nA Z\nB X\nC Y\nC Z\nA Z\nA Z\nC Z\nB X\nB X\nA Z\nA Z\nB X\nA Z\nA Z\nC Z\nA Z\nA Z\nA X\nC Z\nC Y\nA Z\nA Z\nA Z\nA Z\nC Z\nA Z\nA Z\nB Z\nA Z\nC Y\nA Z\nA Z\nB Y\nA Z\nA Z\nB X\nA Z\nB X\nA Z\nA Z\nC Y\nA Y\nC Y\nB Z\nB X\nB Y\nA Z\nA Z\nC Y\nA Z\nA Y\nB Z\nA Z\nC Y\nA Z\nA Z\nA X\nA Z\nB Y\nB Y\nA Z\nA Z\nA Z\nC Z\nC Z\nA Y\nC Y\nB X\nA Y\nB X\nB Y\nC X\nC Y\nC Y\nA Z\nC Z\nA Z\nA Z\nA Z\nB X\nA Z\nA Z\nA Z\nA Z\nA Y\nB X\nA Z\nA Z\nB X\nA Z\nA Z\nA Z\nA Z\nA X\nC Y\nB X\nA Z\nA Y\nC Y\nC Y\nA X\nA Z\nC X\nC Z\nA Z\nC X\nA Z\nA Z\nB Y\nA Z\nA Z\nA Z\nB X\nA Z\nA Z\nB X\nB X\nA Z\nA Z\nC Z\nC Z\nA Z\nC Z\nB X\nA Z\nA Z\nB X\nC Z\nC Z\nC Y\nC Z\nA Z\nB X\nA X\nC Z\nA X\nC Z\nA Z\nA Z\nA Z\nA Z\nA Z\nB X\nA Z\nB X\nC Y\nA Z\nA Z\nA Z\nC Z\nA Y\nA Y\nB Y\nA Z\nA Z\nC Y\nC Z\nB X\nB X\nA X\nC Z\nB X\nA Z\nA Z\nA Z\nB Z\nA Z\nC Y\nB X\nA Z\nA Z\nA Y\nB Y\nC Z\nC Z\nA Z\nA Z\nA Z\nB Y\nA Z\nC Y\nB X\nB Z\nC X\nB X\nC Y\nA X\nC Z\nA Z\nB X\nC X\nA Y\nC X\nA Z\nB X\nB X\nA Z\nA Z\nC Z\nB X\nB Z\nC Y\nC Z\nA Z\nB Y\nA Z\nA Z\nB X\nC Y\nA Z\nC Z\nA Z\nB Z\nC Z\nC Z\nA Z\nC Y\nA Z\nA Z\nA Z\nC Z\nC X\nB Y\nC Y\nA Z\nC Y\nC Y\nC X\nC Y\nA Z\nC Y\nC Y\nC X\nC X\nA Z\nB X\nA Z\nC Y\nA Z\nB X\nB X\nB X\nB X\nB X\nB Y\nA Z\nA Z\nC Z\nA Z\nA Z\nA Z\nC Z\nC Z\nC Z\nA Z\nA Z\nA Y\nA Z\nA Z\nA Y\nA X\nC Z\nA Z\nA Z\nC Z\nB X\nC Z\nB Y\nC Z\nA Y\nA Z\nC Y\nB X\nA Z\nC Y\nA Z\nC Z\nC Y\nB X\nA Z\nA Z\nA Z\nA Z\nA Z\nC X\nC Z\nA Z\nA Z\nA Z\nC Z\nA Z\nB X\nA Z\nA X\nA Z\nB X\nA Z\nC Z\nA Z\nA Y\nB X\nB Z\nA Z\nB X\nA Z\nA Z\nB Y\nA Z\nA Z\nC Y\nB Y\nC X\nA Z\nA Z\nA Z\nC Z\nA Z\nA Z\nA Z\nC Z\nA Z\nC Y\nB X\nA Z\nA Z\nC X\nA Z\nC Z\nA Z\nB Y\nA Z\nA Y\nC Z\nC Z\nA Y\nA Y\nA Z\nA X\nA Z\nA Z\nB X\nA Z\nA Z\nB X\nC Z\nA Z\nA Y\nB X\nA Z\nA Z\nC Z\nA Z\nA Z\nB X\nB Z\nA Z\nA X\nB Y\nA Z\nB X\nA Z\nC Z\nB X\nC Y\nA Z\nB X\nA Z\nA Z\nA Z\nB Z\nA Z\nC Z\nA Z\nC Z\nB X\nA Z\nB Z\nA Z\nC Z\nC Z\nB Y\nC Z\nA Z\nA Z\nC Y\nA Z\nA Z\nB X\nB Y\nC Z\nA Z\nC Z\nA Z\nC Z\nA Z\nB X\nA X\nB Y\nA Z\nC Z\nA Z\nC Z\nC Y\nB X\nC Z\nC Z\nB Y\nB X\nC Z\nB X\nC Y\nA Z\nC Y\nC Y\n" <> ...}
```

```elixir
translate = %{"A" => :rock, "B" => :paper, "C" => :scissors}
points = %{rock: 1, paper: 2, scissors: 3}

defmodule Day02 do
  @wins %{paper: :rock, rock: :scissors, scissors: :paper}

  def score(a, a), do: 3
  def score(a, b) when :erlang.map_get(a, @wins) == b, do: 6
  def score(_, _), do: 0

  for {a, b} <- @wins do
    def wins_with(unquote(a)), do: unquote(b)
    def loses_to(unquote(b)), do: unquote(a)
  end
end

freqs =
  puzzle_input
  |> String.split("\n", trim: true)
  |> Enum.map(fn <<a, ?\s, b>> -> {translate[<<a>>], <<b>>} end)
  |> Enum.frequencies()
```

<!-- livebook:{"output":true} -->

```
%{
  {:paper, "X"} => 395,
  {:paper, "Y"} => 146,
  {:paper, "Z"} => 65,
  {:rock, "X"} => 77,
  {:rock, "Y"} => 113,
  {:rock, "Z"} => 1011,
  {:scissors, "X"} => 96,
  {:scissors, "Y"} => 242,
  {:scissors, "Z"} => 355
}
```

## Task 1

I really dislike this task, because description of the task suggested that the goal is to find best strategy that do not win all rounds. Instead it is supposed to play strategy using **exact** steps defined in the example.

Very poor wording.

```elixir
strategy = %{"Y" => :paper, "X" => :rock, "Z" => :scissors}

freqs
|> Enum.reduce(0, fn {{b, c}, v}, acc ->
  choice = strategy[c]
  result = Day02.score(choice, b)
  acc + v * (points[choice] + result)
end)
```

<!-- livebook:{"output":true} -->

```
9241
```

## Task 2

```elixir
freqs
|> Enum.reduce(0, fn {{b, strategy}, v}, acc ->
  choice =
    case strategy do
      "X" -> Day02.wins_with(b)
      "Y" -> b
      "Z" -> Day02.loses_to(b)
    end

  result = Day02.score(choice, b)
  acc + v * (points[choice] + result)
end)
```

<!-- livebook:{"output":true} -->

```
14610
```