图论算法

求SAP矩阵的基本思想是图的最短路的问题。

由于铁路的运输费用与线路的长度不是线性关系，必须对铁路网做一些预处理才能套用图的标准最短算法。

-SAP matrix graph theory algorithm for getting the basic idea is to map the shortest path problem. Since the railway transport costs and the length of line is not a linear relationship, we must do some preprocessing on the rail network to apply a standard graph algorithm shortest.