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.
从技术层面来看，加密技术、访问控制和安全审计是三大核心防线。
[사설]2년 만에 꺾인 강남·용산 집값… 아직 갈 길 멀다
音頻加註文字，陸劇《甄嬛傳》「馬拉松」如何成為台灣年輕人過年的「文化習俗」？Skip content and continue reading中共黨報批歷史劇《甄嬛傳》宣揚犬儒主義2013年9月19日