From 4879d7a7d2fd9c298bc5ca9a87bb37ccc555d82b Mon Sep 17 00:00:00 2001
From: Adam Millerchip <adam@millerchip.net>
Date: Tue, 10 Dec 2024 17:15:25 +0900
Subject: [PATCH] Simplify 2024 Day 10 to remove MapSets

---
 2024/day10.exs | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/2024/day10.exs b/2024/day10.exs
index 76d4d22..9733ce7 100644
--- a/2024/day10.exs
+++ b/2024/day10.exs
@@ -2,16 +2,15 @@
 defmodule Day10 do
   def part1({grid, zeros}) do
     zeros
-    |> Enum.map(fn point -> MapSet.size(score(point, grid, 0)) end)
+    |> Enum.map(fn point -> point |> score(grid, 0) |> Enum.uniq() |> Enum.count() end)
     |> Enum.sum()
   end
 
-  def score(point, _grid, 9), do: MapSet.new([point])
+  def score(point, _grid, 9), do: [point]
 
   def score({x, y}, grid, height) do
     find_neighbours(x, y, height, grid)
-    |> Enum.map(fn {point, _} -> score(point, grid, height + 1) end)
-    |> Enum.reduce(MapSet.new(), &MapSet.union/2)
+    |> Enum.flat_map(fn {point, _} -> score(point, grid, height + 1) end)
   end
 
   def find_neighbours(x, y, height, grid) do
@@ -24,15 +23,7 @@ defmodule Day10 do
 
   def part2({grid, zeros}) do
     zeros
-    |> Enum.map(fn point -> score2(point, grid, 0) end)
-    |> Enum.sum()
-  end
-
-  def score2(_point, _grid, 9), do: 1
-
-  def score2({x, y}, grid, height) do
-    find_neighbours(x, y, height, grid)
-    |> Enum.map(fn {point, _} -> score2(point, grid, height + 1) end)
+    |> Enum.map(fn point -> point |> score(grid, 0) |> Enum.count() end)
     |> Enum.sum()
   end