euler-067

# Read the triangle from the file and convert it to a 2D array of integers
triangle = File.readlines("triangle.txt").map do |line|
  line.split.map(&:to_i)
end

# Start from the second-to-last row and move upwards
(triangle.length - 2).downto(0) do |current_row|
  triangle[current_row].each_with_index do |value, index|
    # Find the maximum of the two adjacent numbers in the row below
    left_path = triangle[current_row + 1][index]
    right_path = triangle[current_row + 1][index + 1]
    max_path = [left_path, right_path].max

    # Add the maximum path value to the current number
    triangle[current_row][index] += max_path
  end
end

# The maximum total is now at the top of the triangle
maximum_total = triangle[0][0]

puts "The maximum total from top to bottom of the triangle is: #{maximum_total}"