说明：  . Dijkstra算法是一种用来解决最短路径问题的算法。作为前端程序员了解一些经典的算法还是很有必要的。Dijkstra算法是从一个顶点到其余各顶点的最短路径算法，解决的是有权图中最短路径问题。Dijkstra算法主要特点是以起始点为中心向外层层扩展，直到扩展到终点为止。
(Dijkstra algorithm is an algorithm used to solve the shortest path problem. As a front-end programmer, it is necessary to understand some classical algorithms. Dijkstra algorithm is the shortest path algorithm from one vertex to the other vertices. It solves the shortest path problem in weighted graph. The main feature of the Dijkstra algorithm is to expand from the starting point to the center, extending to the endpoint until the end)