K最短路问题。大家现在已经知道了如何求单源点最短路径问题，但在实际应用中，有时候需要除了需要知道最短路径外，尚需求解次最短路或第三最短路，即要知道多条最短路，并排出其长度增加的顺序。如在通信网络中，有时候某条线路中断，则需要找一个替代的方案，这就需要找到几条最短路以备不时之需。这样一类多条最短路问题即称为K最短路问题。-K shortest path problem. We now know how to find single source shortest path problem, but in practice, sometimes need to know the shortest path in addition to, but still need to solve the second or third most short path, that is, to know more than most short and to increase the length of the order of discharge. If the communication network, and sometimes interrupted on certain routes, you need to find an alternative solution, which needs to find the shortest path for a rainy day a few. As a class of more than one shortest path problem is known as the K shortest path problem.