「身為曾經身陷交火漩渦的人，我為這些運動員感到難過，」她表示。
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.
，更多细节参见同城约会
suggested keywords will appear.
Source: Computational Materials Science, Volume 266