The sudo is necessary depending on your choice in the next step.
關恆說，這次的突擊搜查讓他感到吃驚、措手不及，也是完全預料之外的事情，「當時我的心情是很難過，也很擔憂。」，推荐阅读服务器推荐获取更多信息
，更多细节参见同城约会
Now that we can build the tree, let's use it to search. Finding a specific point means starting at the root and asking: which child quadrant contains this coordinate? Then you recurse into that child and ask again. Each level of the tree cuts the search space by roughly three-quarters.。91视频对此有专业解读
* @return pivot最终位置