US-based scientists analysed data from tiger sharks tagged with acoustic transmitters, and found that they took directedpaths from place to place.
美国科学家分析了装在虎鲨上的声学信号传送器中储存的数据，发现他们能够到各处直来直去。
2
For computer processing of the directed digraph, it is expressed by a matrix, and then the longest directedpaths can be obtained through matrices multiplication.
为了便于计算机处理，将有向图用矩阵表示，通过有向图矩阵的乘法运算搜索最长的有向路径。
3
Is it practical to store unique paths through a directed acyclic graph?