最大流和最小截算法，在这个函数的编制中存在一个细节，当任取一个已标号未检查的点的时候，我取的最靠前的点。如果加进随机选取的语句，每次运行程序可能会出现不同的最大流结果。-Maximum flow and minimum cut algorithms, in this function exists in the preparation of a detail, if any label does not take a check point has been, I get the most front point. If the statement is added to randomly selected for each run the program may come up with different results of maximum flow.