all_diagonals.rb

matrix = ('a'..'y').each_slice(5).to_a

def all_diagonals(m)
  len = m[0].length
  final = Array.new(2*len - 1){[]}

  0.upto(len-1) do |i|
    i.downto(0) do |j|
      final[i] << m[i-j][j]
      final[2*len-i-2] << m[len-1-j][j+len-i-1] if 2*len-i-2 != len-1
    end
  end
  final
end


matrix.each { |i| p i }

puts; puts;

p all_diagonals(matrix)