gistfile1.rb

def square1_scramble
  scramble = []
  up_layer = (0..7).map{|i| i%2 == 0 ? 30 : 60}
  down_layer = [up_layer].flatten!
  length = 0
  begin
    up_moves = possible_moves up_layer
    down_moves = possible_moves down_layer
    up_move = up_moves.sample
    down_moves.delete 0 if up_move == 0
    down_move = down_moves.sample
    scramble << [humanize_sq_one_move(up_layer, up_move), humanize_sq_one_move(down_layer, down_move) * -1]
    do_move up_layer, up_move
    do_move down_layer, down_move
    length += up_move == 0 ? 0 : 1
    length += down_move == 0 ? 0 : 1
    do_slice(up_layer, down_layer)
    length += 1
  end while length <= scramble_length + 1
  scramble.map {|s| "(#{s.join(',')})"}.join(' ')
end

def humanize_sq_one_move(layer, move)
  move = layer[0..move - 1].inject(0){|sum, x| x == 30 ? sum + 1 : sum + 2} unless move == 0
  move > 6 ? move - 12 : move
end

def possible_moves(layer)
  layer_moves = []
  layer.length.times do |start|
    sum = 0
    possible = false
    layer.length.times do |i|
      sum += layer[(start + i) % layer.length]
      possible = true if sum == 180
    end
    layer_moves << start if possible
  end
  layer_moves
end

def do_move(layer, l)
  l %= layer.length
  l.times do
    layer << layer.shift
  end
  layer
end

def do_slice(up, down)
  sum = 0
  small_up, big_up = up.partition {|n| sum += n; sum <= 180}
  small_down, big_down = down.partition {|n| sum += n; sum <= 540}
  up.replace(small_down.reverse + big_up)
  down.replace(small_up.reverse + big_down)
end