Day 3

2023/day3/p1.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+arr = []
+File.foreach('./2023/day3/data') do |line|
+  arr << line.strip.split('').append('.')
+end
+
+def int?(str)
+  str.to_i.to_s == str
+end
+
+def special_char?(char)
+  char != '.' and !int?(char)
+end
+
+def adj_special_char?(arr, row_index, char_index)
+  [[-1, 0], [1, 0], [0, -1], [0, 1], [1, 1], [-1, -1], [-1, 1], [1, -1]].each do |offset|
+    next 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)
+    return true if special_char?(arr[row_index + offset[0]][char_index + offset[1]])
+  end
+  false
+end
+
+res = 0
+arr.each_with_index do |row, row_index|
+  current_number = 0
+  found_special_char = false
+  row.each_with_index do |el, col_index|
+    if int? el
+      current_number *= 10
+      current_number += el.to_i
+      found_special_char ||= adj_special_char?(arr, row_index, col_index)
+    elsif found_special_char
+      res += current_number
+      current_number = 0
+      found_special_char = false
+    else
+      current_number = 0
+    end
+  end
+end
+
+puts res