Advent Of Code – Day 02

Data

stream = File.stream!("/Users/pw/src/weiland/adventofcode/2022/input/02.txt")
stream

convert_line = fn line ->
  line
  |> String.replace("\n", "")
  |> String.split(" ")
end

stream = Stream.map(stream, convert_line)

Code

Part one:

calculate_score = fn line ->
  [op, me] = line

  case {op, me} do
    {"A", "X"} -> 4
    {"A", "Y"} -> 8
    {"A", "Z"} -> 3
    {"B", "X"} -> 1
    {"B", "Y"} -> 5
    {"B", "Z"} -> 9
    {"C", "X"} -> 7
    {"C", "Y"} -> 2
    {"C", "Z"} -> 6
    _ -> 999_999
  end
end

stream
|> Enum.map(calculate_score)
|> Enum.sum()

Part two:

calculate_score_two = fn line ->
  [op, me] = line

  case {op, me} do
    {"A", "X"} -> 3
    {"A", "Y"} -> 4
    {"A", "Z"} -> 8
    {"B", "X"} -> 1
    {"B", "Y"} -> 5
    {"B", "Z"} -> 9
    {"C", "X"} -> 2
    {"C", "Y"} -> 6
    {"C", "Z"} -> 7
    _ -> 999_999
  end
end

stream
|> Enum.map(calculate_score_two)
|> Enum.sum()