AdventOfCode/2018/day2/part1.exs

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Elixir
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2021-12-26 13:10:19 +00:00
defmodule Part1 do
def increment_freq(char, freq_map) do
Map.update(freq_map, char, 1, &(&1 + 1))
end
def to_freq_map(str) do
str
|> String.to_charlist()
|> Enum.reduce(%{}, &increment_freq/2)
end
def contains_frequency?(freq_map, freq) do
Map.values(freq_map) |> Enum.member?(freq)
end
def count_twos_and_threes(freq_map, {twos, threes}) do
twos = if contains_frequency?(freq_map, 2), do: twos + 1, else: twos
threes = if contains_frequency?(freq_map, 3), do: threes + 1, else: threes
{twos, threes}
end
def run do
{twos, threes} =
File.stream!("input")
|> Stream.map(&String.trim/1)
|> Stream.map(&to_freq_map/1)
|> Enum.reduce({0, 0}, &count_twos_and_threes/2)
IO.puts("#{twos} * #{threes} = #{twos * threes}")
end
end
Part1.run()