Quadtrees are everywhere spatial data exists. Mapping services use quadtree-like tile pyramids to serve map tiles at different zoom levels (Bing's quadkey system, for example, addresses tiles as base-4 paths). Game engines use them for collision detection and visibility culling. Geographic information systems use spatial indexes to store and query spatial datasets. PostGIS uses GiST indexes (R-tree-style) for spatial queries on geometries, while PostgreSQL's core supports quadtree-like SP-GiST indexes for certain data types like points.
说白了，一个 Skills 专家的应用商店雏形，已经摆在我们面前了。
，更多细节参见heLLoword翻译官方下载
give yours to someone else you are very unlikely to get it back. ATMs, therefore,
Мир Российская Премьер-лига|19-й тур