From f67bc7bd2770c86d59f80ad0784279da45efb1eb Mon Sep 17 00:00:00 2001
From: Alpha Chen <alpha@kejadlen.dev>
Date: Wed, 7 Dec 2022 21:37:03 -0800
Subject: [PATCH] [2022][ruby][8.x]

---
 2022/ruby/day_08.rb | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 2022/ruby/day_08.rb

diff --git a/2022/ruby/day_08.rb b/2022/ruby/day_08.rb
new file mode 100644
index 0000000..aa98b9d
--- /dev/null
+++ b/2022/ruby/day_08.rb
@@ -0,0 +1,37 @@
+# grid = ARGF.read.lines(chomp: true).map {|row| row.chars.map { [_1.to_i, false] }}
+
+# def mark!(ary)
+#   max = -1
+#   ary.each do |tree_counted|
+#     if tree_counted.first > max
+#       max = tree_counted.first
+#       tree_counted[1] = true
+#     end
+#   end
+# end
+
+# grid.each { mark!(_1) }
+# grid.each { mark!(_1.reverse) }
+# grid.transpose.each { mark!(_1) }
+# grid.transpose.each { mark!(_1.reverse) }
+
+# p grid.sum { _1.count(&:last) }
+
+grid = ARGF.read.lines(chomp: true).map { _1.chars.map(&:to_i) }
+
+def score(grid, y, x)
+  tree = grid[y][x]
+
+  [
+    (0...y).to_a.reverse.slice_after {|i| grid[i][x] >= tree }.first,
+    (y+1...grid.size).slice_after {|i| grid[i][x] >= tree }.first,
+    (0...x).to_a.reverse.slice_after {|i| grid[y][i] >= tree }.first,
+    (x+1...grid.size).slice_after {|i| grid[y][i] >= tree }.first,
+  ].compact.map(&:size).inject(:*)
+end
+
+p grid.flat_map.with_index {|row,y|
+  row.map.with_index {|tree,x|
+    score(grid, y, x)
+  }
+}.max