From 1e974c56aeb8a0b0c8c596869a9a823d876e3481 Mon Sep 17 00:00:00 2001
From: Adam Millerchip <adam@millerchip.net>
Date: Mon, 9 Dec 2024 09:23:48 +0900
Subject: [PATCH] Simplify a bit by inlining a function

---
 2024/day8.exs | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/2024/day8.exs b/2024/day8.exs
index 694fc13..32b7f91 100755
--- a/2024/day8.exs
+++ b/2024/day8.exs
@@ -2,22 +2,19 @@
 defmodule Day8 do
   def part1({x, y, frequencies}) do
     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)
     |> MapSet.size()
   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([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
     dy = y_a - y_b
     antinode_1 = {x_a + dx, y_a + dy}
@@ -30,19 +27,16 @@ defmodule Day8 do
 
   def part2({x, y, frequencies}) do
     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)
     |> MapSet.size()
   end
 
-  def find_resonant_harmonics(antennas, x, 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
+  def find_resonant_harmonics({{x_a, y_a}, {x_b, y_b}}, max_x, max_y) do
     dx = x_a - x_b
     dy = y_a - y_b