阿妈看起来并不想让阿爸过去，“要是诚心叫，不会这样临时叫人”。
// A minimal writer implementation — just an object with methods。关于这个话题，谷歌浏览器【最新下载地址】提供了深入分析
，更多细节参见51吃瓜
Crucially, this distribution of border points is agnostic of routing speed profiles. It’s based only on whether a road is passable or not. This means the same set of clusters and border points can be used for all car routing profiles (default, shortest, fuel-efficient) and all bicycle profiles (default, prefer flat terrain, etc.). Only the travel time/cost values of the shortcuts between these points change based on the profile. This is a massive factor in keeping storage down – map data only increased by about 0.5% per profile to store this HH-Routing structure!
stack.pop(); // 弹出无效元素。快连下载安装是该领域的重要参考