What is the greatest product of four adjacent numbers in the same direction (up, down, left, right, or diagonally) in the 20x20 grid?

euler11.rb

class Celery
  def initialize(grid)
    @grid = grid
    @height = grid.length
    @width = grid[0].length
  end
  def self.mini
     [[ 0, 1, 2, 3, 4],
      [10,11,12,13,14],
      [20,21,22,23,24],
      [30,31,32,33,34],
      [40,41,42,43,44]]
  end
  def self.enormous_grid
    [[ 8,  2, 22, 97, 38, 15,  0, 40,  0, 75,  4,  5,  7, 78, 52, 12, 50, 77, 91,  8],
     [49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48,  4, 56, 62,  0],
     [81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30,  3, 49, 13, 36, 65],
     [52, 70, 95, 23,  4, 60, 11, 42, 69, 24, 68, 56,  1, 32, 56, 71, 37,  2, 36, 91],
     [22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80],
     [24, 47, 32, 60, 99,  3, 45,  2, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50],
     [32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70],
     [67, 26, 20, 68,  2, 62, 12, 20, 95, 63, 94, 39, 63,  8, 40, 91, 66, 49, 94, 21],
     [24, 55, 58,  5, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72],
     [21, 36, 23,  9, 75,  0, 76, 44, 20, 45, 35, 14,  0, 61, 33, 97, 34, 31, 33, 95],
     [78, 17, 53, 28, 22, 75, 31, 67, 15, 94,  3, 80,  4, 62, 16, 14,  9, 53, 56, 92],
     [16, 39,  5, 42, 96, 35, 31, 47, 55, 58, 88, 24,  0, 17, 54, 24, 36, 29, 85, 57],
     [86, 56,  0, 48, 35, 71, 89,  7,  5, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58],
     [19, 80, 81, 68,  5, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77,  4, 89, 55, 40],
     [ 4, 52,  8, 83, 97, 35, 99, 16,  7, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66],
     [88, 36, 68, 87, 57, 62, 20, 72,  3, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69],
     [ 4, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18,  8, 46, 29, 32, 40, 62, 76, 36],
     [20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74,  4, 36, 16],
     [20, 73, 35, 29, 78, 31, 90,  1, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57,  5, 54],
     [ 1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52,  1, 89, 19, 67, 48]]
  end

  def down(col,row)
    unless row >= @height - 4 + 1
      0.upto(3).map do |x|
        @grid[row + x][col] or raise [col, row].to_s
      end
    end
  end

  def right(col,row)
    unless col >= @width - 4 + 1
      0.upto(3).map do |x|
        puts "wtf" if @grid[row].nil?
        @grid[row][col + x] or raise [col, row].to_s
      end
    end
  end

  def diagonal_right(col,row)
    unless row >= (@height - 4 + 1) || col >= (@width - 4 + 1)
      (0..3).map do |x|
        @grid[row + x][col + x] or raise [col, row].to_s
      end
    end
  end

  def diagonal_left(col,row)
    unless row >= (@height - 4 + 1) || col - 3 < 0
      (0..3).map do |x|
        @grid[row + x][col - x] or raise [col, row].to_s
      end
    end
  end

  def solve
    result = []
    0.upto(@width - 1).each do |x|
      0.upto(@height - 1).each do |y|
        #[(down x,y), (right x,y), (diagonal_right x,y), (diagonal_left x,y)].each { |action|
        #  result.push(action)
        #}
        result.push down(x, y), right(x, y), diagonal_right(x, y), diagonal_left(x, y)
      end
    end
    result
  end
end

hmmm = Celery.new(Celery.enormous_grid)
p "whaaaaaaat..."
result = hmmm.solve

# okay, so this returns the product:
p result.compact.map{ |x| x.inject(:*)}.max # or .max
p "finito."
# but how do i find the coordinates, also?