def solve(n = 1)
    return true if n == @cubes.length
    rotationCount = 0
    solved = false
    while not solved
      solved = true
      n.times do |i|
        if @cubes[n] == @cubes[i]
          solved = false
          break
        end
      end

      if solved and (solved = solve(n + 1))
        return true
      else
        @cubes[n].rotate
        rotationCount += 1
        if rotationCount > 3
          return false
        end
      end
    end
  end