Range queries ask "what's inside this box?" But sometimes the question is "what's nearest to this location?" This is the nearest neighbor problem, and you don't know how big your search radius should be. The nearest point might be right next to you or far away.
* @param arr 待排序数组
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Truth be told, you could argue that many of these shortcomings are typical of a retro Polaroid-inspired instant camera and, thus, part of the experience. If that’s what you’re looking for, the Flip is the perfect camera for you.
if(p->count == 0) {