forming_a_magic_square.rb

def matrices
  [
    [2, 7, 6, 9, 5, 1, 4, 3, 8],
    [6, 1, 8, 7, 5, 3, 2, 9, 4],
    [8, 3, 4, 1, 5, 9, 6, 7, 2],
    [4, 9, 2, 3, 5, 7, 8, 1, 6],
    [2, 9, 4, 7, 5, 3, 6, 1, 8],
    [4, 3, 8, 9, 5, 1, 2, 7, 6],
    [8, 1, 6, 3, 5, 7, 4, 9, 2],
    [6, 7, 2, 1, 5, 9, 8, 3, 4],
  ]
end

def formingMagicSquare(s)
  s.flatten! # flatten the sqare
  
  min = 1/0.0 # Infinity
  
  matrices.each do |matrix|
    cost = 0
    
    s.each_with_index do |item, index|
      cost += (matrix[index] - item).abs
    end
    
    min = [cost, min].min
  end
  
  min
end