From 8ceaee32a0cac77c11df36f2d55b3e7a6522fb0c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Niemier?= <~@hauleth.dev>
Date: Sat, 6 Dec 2025 09:29:38 +0100
Subject: [PATCH] Add drawing of the board for day 07 of 2025

---
 2025/day07.livemd | 50 ++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

diff --git a/2025/day07.livemd b/2025/day07.livemd
index 65cfc59..b195a18 100644
--- a/2025/day07.livemd
+++ b/2025/day07.livemd
@@ -44,6 +44,8 @@ Enum.reduce(splitters, {MapSet.new([start_col]), 0}, fn splits, {beams, count} -
 end)
 ```
 
+<!-- livebook:{"branch_parent_index":0} -->
+
 ## Part 2
 
 ```elixir
@@ -68,4 +70,50 @@ end)
 |> Enum.sum_by(&elem(&1, 1))
 ```
 
-<!-- livebook:{"offset":1576,"stamp":{"token":"XCP.4O_0Nj7V9wS7w6P8UvTBgpp4vhW57_8fy1nGUUO-kK-Q74Dt1KmWL8qx_FolCKDbpEooq8lZ8yn9tXw9AlKXzLPCKp2hEtIvQvKWtBiSmje0vN9ms0Uqud5m2GxlgCHmtg","version":2}} -->
+<!-- livebook:{"branch_parent_index":0} -->
+
+## Image
+
+```elixir
+height = length([start | rest])
+width = byte_size(start)
+
+{height, width}
+```
+
+```elixir
+Image.new!(width, height)
+|> Image.mutate(fn img ->
+  Image.Draw.point!(img, start_col, 0, color: :yellow)
+
+  splitters
+  |> Enum.with_index(1)
+  |> Enum.reduce(MapSet.new([start_col]), fn {splits, y}, beams ->
+    import MapSet, only: [intersection: 2, difference: 2, union: 2]
+
+    for x <- beams do
+      Image.Draw.point!(img, x, y, color: :green)
+    end
+
+    for x <- splits do
+      Image.Draw.point!(img, x, y, color: :red)
+    end
+    
+    hits = intersection(beams, splits)
+    new_beams = for hit <- hits, dx <- [-1, 1], into: MapSet.new(), do: hit + dx
+    beams = beams |> difference(hits) |> union(new_beams)
+
+    beams
+  end)
+
+  #for {row, y} <- Enum.with_index(splitters, 1),
+  #    x <- row,
+  #  do: Image.Draw.point!(img, x, y, color: :red)
+
+  img
+end)
+|> then(fn {:ok, img} -> img end)
+|> Image.resize!(5, interpolate: :nearest)
+```
+
+<!-- livebook:{"offset":2629,"stamp":{"token":"XCP.lHomXHh84XridtwMBP5AP7BXVVCvUC-jx1w-h7SzIFygBNyHhdS1qTLyp97LGQ3Rf1f4to4IjQtJmlsi-0PrxC2vUjGg97fvP9zvt5n0IxMkwLnFfvafaIDjJSsZLX1Bcg","version":2}} -->
-- 
2.51.2