摘要：
参考：貌似网上没几个对的题解1.http://blog.csdn.net/juststeps/article/details/8772653?reload2.wiki：The transitive closure of a directed acyclic graph (DAG) is the reachability relation of the DAG and a strict partial order.1.先用floyd求出各点间的可达性，这道题可以包含正负环，所以用floyd算法求出来的类似传递闭包的东西不是传递闭包2.运行非队列版的Bellman-Ford算法，对每个点可能地松弛 阅读全文
