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