The so-called reaching algorithm can solve the shortest path problem (i.e., the problem of finding the graph
geodesic between two given nodes) on an 
-edge graph in 
steps for an acyclic digraph.
This algorithm allows paths such that edges traversed in the direction opposite their
orientation have a negative length.
No other algorithm can have better complexity because any other algorithm would have to at least examine every edge, which would itself take 
steps.
