Day 11

days/day11.rb

@@ -0,0 +1,88 @@
+require_relative '../lib/aoc'
+require_relative '../lib/grid'
+
+module Day11
+	extend AOC::Day
+
+	@num = 11
+	@ans_test1 = 374
+	@ans_test2 = 82000210
+
+	def self.solve_part1(input)
+		galaxies, empty_rows, empty_cols = parse_input(input)
+
+		r = 0
+		galaxies.each_with_index do |g, i|
+			(i+1...galaxies.length).each do |j|
+				to_g = galaxies[j]
+				min_x, max_x = [g[0], to_g[0]].minmax
+				min_y, max_y = [g[1], to_g[1]].minmax
+
+				s = (max_x-min_x) + (max_y-min_y)
+				s += empty_cols.count{|x| x.between?(min_x, max_x)}
+				s += empty_rows.count{|y| y.between?(min_y, max_y)}
+				r += s
+			end
+		end
+		return r
+	end
+
+	def self.solve_part2(input)
+		galaxies, empty_rows, empty_cols = parse_input(input)
+
+		r = 0
+		galaxies.each_with_index do |g, i|
+			(i+1...galaxies.length).each do |j|
+				to_g = galaxies[j]
+				min_x, max_x = [g[0], to_g[0]].minmax
+				min_y, max_y = [g[1], to_g[1]].minmax
+
+				s = (max_x-min_x) + (max_y-min_y)
+				s += empty_cols.count{|x| x.between?(min_x, max_x)}*999999
+				s += empty_rows.count{|y| y.between?(min_y, max_y)}*999999
+				r += s
+			end
+		end
+		return r
+	end
+
+	def self.parse_input(input)
+		grid = Grid::string_to_grid(input)
+		max_x = grid[0].length-1
+		max_y = grid.length-1
+
+		empty_rows = []
+		empty_cols = []
+		(0..max_x).each do |x|
+			empty = true
+			(0..max_y).each do |y|
+				if grid[y][x] != "."
+					empty = false
+					break
+				end
+			end
+			empty_cols << x if empty
+		end
+		(0..max_y).each do |y|
+			empty = true
+			(0..max_x).each do |x|
+				if grid[y][x] != "."
+					empty = false
+					break
+				end
+			end
+			empty_rows << y if empty
+		end
+
+		galaxies = []
+		grid.each_with_index do |row, y|
+			row.split("").each_with_index do |c, x|
+				galaxies << [x, y] if c == "#"
+			end
+		end
+
+		return [galaxies, empty_rows, empty_cols]
+	end
+end
+
+Day11.run

inputs/test/test_input11

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+...#......
+.......#..
+#.........
+..........
+......#...
+.#........
+.........#
+..........
+.......#..
+#...#.....