美国二手书零售商 Better World Books，以及总部位于英国的 World of Books，每次采购动辄数万册。内部文件还显示，员工曾讨论接洽纽约公共图书馆，甚至提到可以找某家长期资金不足的新图书馆。
Point lookups are useful, but the operation you'll reach for more often is a range query: give the tree a rectangular region and retrieve every point inside it, without scanning the entire dataset.
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02:00, 28 февраля 2026Путешествия
characters each, onto the middle of the card. The machines didn't actually punch
* 时间复杂度：O(n)，空间复杂度：O(n)