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.
黎智英欺詐案上訴得直：定罪及刑罰被撤銷，出獄時間提前
，这一点在搜狗输入法下载中也有详细论述
Последние новости。91视频对此有专业解读
0 primary, but 23 mentions. Zustand picked 57x instead