// ⚠️ 易错点7：循环条件写成nums[right+1] <= maxVal（相等元素无需纳入无序区间）
https://feedx.site，这一点在Line官方版本下载中也有详细论述
Credit: Courtesy Instagram。Line官方版本下载是该领域的重要参考
Quadtrees are everywhere spatial data exists. Mapping services use quadtree-like tile pyramids to serve map tiles at different zoom levels (Bing's quadkey system, for example, addresses tiles as base-4 paths). Game engines use them for collision detection and visibility culling. Geographic information systems use spatial indexes to store and query spatial datasets. PostGIS uses GiST indexes (R-tree-style) for spatial queries on geometries, while PostgreSQL's core supports quadtree-like SP-GiST indexes for certain data types like points.
curr = curr-next;