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。-In this function, there is a compilation of details, when the term of office does not take a grade-point inspection, I take the point of the most high. If the added words were