Title
Topological orderings of weighted directed acyclic graphs
Abstract
We call a topological ordering of a weighted directed acyclic graph non-negative if the sum of weights on the vertices in any prefix of the ordering is non-negative. We investigate two processes for constructing non-negative topological orderings of weighted directed acyclic graphs. The first process is called a mark sequence and the second is a generalization called a mark-unmark sequence. We answer a question of Erickson by showing that every non-negative topological ordering that can be realized by a mark-unmark sequence can also be realized by a mark sequence. We also investigate the question of whether a given weighted directed acyclic graph has a non-negative topological ordering. We show that even in the simple case when every vertex is a source or a sink the question is NP-complete. We introduce a graph algorithm called a mark-unmark sequence for finding topological orderings of directed acyclic graphs.We show that if a directed acyclic graph has a non-negative mark-unmark sequence, then it has non-negative mark sequence.We show that it is NP-hard to decide if a directed acyclic graph has a non-negative topological ordering.
Year
DOI
Venue
2016
10.1016/j.ipl.2016.04.007
Inf. Process. Lett.
Keywords
Field
DocType
Topological ordering,Directed acyclic graph,Graph Algorithms
Acyclic dependencies principle,Discrete mathematics,Topology,Combinatorics,Path (graph theory),Topological sorting,Directed acyclic graph,Directed acyclic word graph,Feedback arc set,Mathematics,Moral graph,Topological graph
Journal
Volume
Issue
ISSN
116
9
0020-0190
Citations 
PageRank 
References 
0
0.34
1
Authors
4
Name
Order
Citations
PageRank
Dániel Gerbner14621.61
Balázs Keszegh215624.36
Cory Palmer34410.33
Dömötör Pálvölgyi4153.79