The efficiency depends on the query size relative to the data distribution. A small query in a sparse region prunes almost everything. A query that covers the whole space prunes nothing (because every node overlaps), degenerating to a brute-force scan. The quadtree gives you the most benefit when your queries are spatially local, which is exactly the common case for map applications, game physics, and spatial databases.
回顾历史，1960年代，Boswell基金会提供120万美元匹配赠款，撬动居民募捐，建成了第一家医院；1988年，Sun Health基金会捐赠900万美元，建成第二家医院。截至目前，两大基金会累计筹集超过5亿美元，支撑着医院从无到有、从基础到现代化的每一步。，推荐阅读同城约会获取更多信息
美股收盘：道指月线10连涨，美国KBW银行指数创去年4月来最大单日跌幅。谷歌浏览器【最新下载地址】对此有专业解读
The firm said the job cuts should deliver annual savings of around £40m and did not specify when the job cuts would be implemented, but said most of the savings would be made this year.