Michael returned to Silicon Valley where, following a brief run at social media analytics company Klout, he joined Uber in 2013 as chief business officer and a close lieutenant to CEO Travis Kalanick. Over the next four years, he helped orchestrate one of the most aggressive expansions in corporate history, in which Uber raised nearly $15 billion and saw its valuation soar to roughly $70 billion.
圖像來源，Getty Images
，更多细节参见体育直播
A quadtree does the same thing for two-dimensional space. It takes a rectangular region and divides it into four equal quadrants: northwest, northeast, southwest, southeast. If a quadrant has too many points in it, it subdivides again and again. Each subdivision creates smaller and smaller cells where points are densely packed.。咪咕体育直播在线免费看是该领域的重要参考
AFP via Getty Images