「如果做太慢就賺不夠錢，大家都不能停下來，要不斷加班。」
/root → /var/roothome
，这一点在WPS官方版本下载中也有详细论述
* 时间复杂度：O(n log n)（主要来自排序），空间复杂度：O(n)
巨亏1800亿元，玛莎拉蒂母公司业绩爆雷
This is the same idea behind binary search. In a sorted array, you compare against the middle element and eliminate half the remaining candidates. In a quadtree, you choose one of four quadrants and ignore the other three regions. Each level narrows the search space by a factor of four instead of two.