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Simplify a bit by inlining a function

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Adam Millerchip 2024-12-09 09:23:48 +09:00
parent 9345419941
commit 1e974c56ae
1 changed files with 12 additions and 18 deletions
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30
2024/day8.exs
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@ -2,22 +2,19 @@
defmodule Day8 do defmodule Day8 do
def part1({x, y, frequencies}) do def part1({x, y, frequencies}) do
Enum.reduce(frequencies, MapSet.new(), fn antennas, antinodes -> Enum.reduce(frequencies, MapSet.new(), fn antennas, antinodes ->
MapSet.union(antinodes, find_antinodes(antennas, x, y)) antennas
|> find_pairs()
|> Enum.flat_map(fn pair -> find_antinodes(pair, x, y) end)
|> MapSet.new()
|> MapSet.union(antinodes)
end) end)
|> MapSet.size() |> MapSet.size()
end end
def find_antinodes(antennas, x, y) do
antennas
|> find_pairs()
|> Enum.flat_map(fn pair -> calc_antinodes(pair, x, y) end)
|> MapSet.new()
end
def find_pairs([_]), do: [] def find_pairs([_]), do: []
def find_pairs([a | rest]), do: for(b <- rest, do: {a, b}) ++ find_pairs(rest) def find_pairs([a | rest]), do: for(b <- rest, do: {a, b}) ++ find_pairs(rest)
def calc_antinodes({{x_a, y_a}, {x_b, y_b}}, max_x, max_y) do def find_antinodes({{x_a, y_a}, {x_b, y_b}}, max_x, max_y) do
dx = x_a - x_b dx = x_a - x_b
dy = y_a - y_b dy = y_a - y_b
antinode_1 = {x_a + dx, y_a + dy} antinode_1 = {x_a + dx, y_a + dy}
@ -30,19 +27,16 @@ defmodule Day8 do
def part2({x, y, frequencies}) do def part2({x, y, frequencies}) do
Enum.reduce(frequencies, MapSet.new(), fn antennas, antinodes -> Enum.reduce(frequencies, MapSet.new(), fn antennas, antinodes ->
MapSet.union(antinodes, find_resonant_harmonics(antennas, x, y)) antennas
|> find_pairs()
|> Enum.flat_map(fn pair -> find_resonant_harmonics(pair, x, y) end)
|> MapSet.new()
|> MapSet.union(antinodes)
end) end)
|> MapSet.size() |> MapSet.size()
end end
def find_resonant_harmonics(antennas, x, y) do def find_resonant_harmonics({{x_a, y_a}, {x_b, y_b}}, max_x, max_y) do
antennas
|> find_pairs
|> Enum.flat_map(fn pair -> calc_resonant_harmonics(pair, x, y) end)
|> MapSet.new()
end
def calc_resonant_harmonics({{x_a, y_a}, {x_b, y_b}}, max_x, max_y) do
dx = x_a - x_b dx = x_a - x_b
dy = y_a - y_b dy = y_a - y_b