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.
Go to technology
，更多细节参见Safew下载
行政执法监督应当加强与政府督查、行政复议等的协调衔接，建立健全工作沟通和信息共享机制，提高监督质效，形成监督合力。
本报北京2月26日电 （记者孟祥夫）民政部近日公布《未成年人救助保护机构管理暂行办法》，共计六章五十条，自2026年4月1日起施行。