aoc/2020/lib/days/day7.ex

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Elixir
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2023-04-17 18:18:20 +00:00
defmodule AOC.Day7 do
def parse_input(lines), do: parse_input(lines, %{})
def parse_input([], acc), do: acc
def parse_input([str | tl], acc) do
[container, str] = String.split(str, " bags contain ")
inner =
str
|> String.split(", ")
|> Enum.map(fn
"no other bags." ->
[]
bags ->
[num, adj1, adj2, _] = String.split(bags)
{String.to_integer(num), "#{adj1} #{adj2}"}
end)
|> List.flatten()
parse_input(tl, Map.put(acc, container, inner))
end
def find_golden_containers(map) do
map
|> Map.keys()
|> Enum.filter(fn
"shiny gold" -> false
bag -> find_golden_containers(map, bag)
end)
end
def find_golden_containers(_, "shiny gold"), do: true
def find_golden_containers(map, bag) do
map[bag]
|> Enum.map(fn {_, x} -> find_golden_containers(map, x) end)
|> Enum.any?()
end
def part1 do
AOC.Util.input_lines(7, 1)
|> parse_input()
|> find_golden_containers()
|> Enum.count()
end
def count_bags(map), do: count_bags(map, "shiny gold")
def count_bags(map, bag) do
map[bag]
|> Enum.map(fn {n, x} -> n * (count_bags(map, x) + 1) end)
|> Enum.sum()
end
def part2 do
AOC.Util.input_lines(7, 1)
|> parse_input()
|> count_bags()
end
end