Deleting vertices to bound path length
Doowon Paik, Sudhakar M. Reddy, Sartaj K. Sahni · IEEE Transactions on Computers · 1994
Examines the vertex deletion problem for weighted directed acyclic graphs (WDAGs). The objective is to delete the fewest number of vertices so that the resulting WDAG has no path of length >/spl delta/. Several simplified versions of this problem are shown to be NP-hard. However, the problem is solved in linear time when the WDAG is a rooted tree, and in quadratic time when the WDAG is a series-parallel graph.>