A deeper debt hole
The spatial view (the grid of rectangles) and the tree view (the hierarchy of nodes) represent the same structure. Searching for a point means walking down the tree: at each node, you check which of the four children contains your target coordinate and recurse into that child. You never visit the other three.
。关于这个话题，safew官方版本下载提供了深入分析
（本报记者赵成、吴丹、朱隽、王昊男、侯琳良、杨文明、王云娜、刘军国、李心萍、寇江泽、李林蔚、常钦、刘新吾、郑洋洋、李俊杰）
"But by proving the technology it really opens the door for an economically viable product, where things can be made in space and return to Earth and have use and benefit to everybody on Earth. And that's really exciting."
两汉至北朝近800年的风云变幻，在东魏北齐时代的邺城画上了一个句号，最终奠定了隋唐盛世的文化基因。