Day 3

2023/day3/p2.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+arr = []
+gear_map = {}
+
+File.foreach('./2023/day3/data') do |line|
+  arr << line.strip.split('').append('.')
+end
+
+def int?(str)
+  str.to_i.to_s == str
+end
+
+def has_gear?(arr, row_index, char_index)
+  [[-1, 0], [1, 0], [0, -1], [0, 1], [1, 1], [-1, -1], [-1, 1], [1, -1]].each do |offset|
+    if (row_index + offset[0]).negative? || (char_index + offset[1]).negative? || (row_index + offset[0] >= arr.length) || (char_index + offset[1] >= arr[row_index].length)
+      next
+    end
+    return [row_index + offset[0], char_index + offset[1]] if arr[row_index + offset[0]][char_index + offset[1]] == '*'
+  end
+  nil
+end
+
+res = 0
+arr.each_with_index do |row, row_index|
+  current_number = 0
+  connected_gears = []
+  row.each_with_index do |el, col_index|
+    if el.to_i.to_s == el
+      current_number *= 10
+      current_number += el.to_i
+      g = has_gear?(arr, row_index, col_index)
+      connected_gears << g unless g.nil?
+    elsif connected_gears.length.positive?
+      connected_gears.each do |gear|
+        gear_map[gear.to_s] = [] if gear_map[gear.to_s].nil?
+        gear_map[gear.to_s] << current_number unless gear_map[gear.to_s].include?(current_number)
+      end
+      current_number = 0
+      connected_gears = []
+    else
+      current_number = 0
+    end
+  end
+end
+
+gear_map.each_value do |value|
+  res += value[0] * value[1] if value.length == 2
+end
+
+puts res