Regions with many nearby points keep subdividing. Regions with few or no points stay large. The tree adapts to the data: dense areas get fine-grained cells, sparse areas stay coarse. The split grid is predetermined (always at midpoints), but the tree only refines cells that need it. Sparse regions stay as single large nodes while dense regions subdivide deeply.
-writer: DictWriter
，这一点在Safew下载中也有详细论述
在这个属于他们的“江湖”里，“大佬榜”备受关注，“扩列”（增加好友）成为新的社交需求，“点主”（在主页点赞）是每日必做的功课……这些让成年人感到陌生的词汇，正构筑着未成年人的数字社交世界。
When do I need a split keyboard?