SearcharxivSearch

arXiv · 1812.02507

On the Enumeration and Counting of Bicriteria Temporal Paths

Abstract

We discuss the complexity of path enumeration and counting in weighted temporal graphs. In a weighted temporal graph, each edge has an availability time, a traversal time and some real cost. We introduce two bicriteria temporal min-cost path problems in which we are interested in the set of all efficient paths with low cost and short duration or early arrival time, respectively. However, the number of efficient paths can be exponential in the size of the input. For the case of strictly positive edge costs we are able to provide algorithms that enumerate the set of efficient paths with polynomial time delay and polynomial space. If we are only interested in the set of Pareto-optimal solutions and not in the paths themselves, then these can be determined in polynomial time if all edge costs are nonnegative. In addition, for each Pareto-optimal solution, we are able to find an efficient path in polynomial time. On the negative side, we prove that counting the number of efficient paths is #P-complete, even in the non-weighted single criterion case.

Explore related subjects

Keep this discovery

BibTeXRIS

Petra Mutzel, Lutz Oettershagen. 2018-12-06. On the Enumeration and Counting of Bicriteria Temporal Paths. https://arxiv.org/abs/1812.02507

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

The Computational Complexity of Holant Problems on 4-regular Graphs from the Stable Subgroup Sequence of $SL(2,\mathbb{C})$

The Holant framework provides a general setting for studying counting problems and includes graph homomorphisms (\#GH) and counting constraint satisfaction problems (\#CSP) as special cases. Over the past twenty years, a series of computational complexity dichotomies have been established for Holant problems, but the classification for complex-valued signatures is still open. The main obstacle is the case in which all signatures have even arity. In this paper, we establish a dichotomy for Holant problems with a complex-valued 4-ary signature, which is a key base case for the full classification of Holant problems. We present a new strategy by introducing Schur's theorem, the classification of finite subgroups of $\mathrm{SL}(2,\mathbb{C})$ and stable subgroup sequences into the proof. These new techniques are of independent interest.

cs.CC

Topology inside NC$^1$

We show that ACC$^0$ is precisely what can be computed with constant-width circuits of polynomial size and polylogarithmic genus. This extends a characterization given by Hansen, showing that planar constant-width circuits also characterize ACC$^0$. Thus polylogarithmic genus provides no additional computational power in this model. We consider other generalizations of planarity, including crossing number and thickness. We show that constant-width circuits of polynomial size and thickness two already suffice to capture all of NC$^1$.

cs.CC