Reconfiguration of satisfying assignments and subset sums: Easy to find, hard to connect
Author(s)
Demaine, Erik D
DownloadSubmitted version (502.2Kb)
Publisher with Creative Commons License
Publisher with Creative Commons License
Creative Commons Attribution
Terms of use
Metadata
Show full item recordAbstract
We consider the computational complexity of reconfiguration problems, in which one is given two combinatorial configurations satisfying some constraints, and is asked to transform one into the other using elementary operations, while satisfying the constraints at all times. Such problems appear naturally in many contexts, such as model checking, motion planning, enumeration, sampling, and recreational mathematics. We provide hardness results for problems in this family, in which the constraints and operations are particularly simple. More precisely, we prove the PSPACE-completeness of the following decision problems: • Given two satisfying assignments of a planar monotone instance of NAE 3-SAT, can one assignment be transformed into the other by a sequence of variable flips such that the formula remains satisfied at every step? • Given two subsets of a set S of integers with the same sum, can one subset be transformed into the other by adding or removing at most three elements of S at a time, such that the intermediate subsets also have the same sum? • Given two points in {0,1}n contained in a polytope P specified by a constant number of linear inequalities, is there a path in the n-hypercube connecting the two points and contained in P? These problems can be interpreted as reconfiguration analogues of standard problems in NP. Interestingly, the sets of instances that appear as input to the reconfiguration problems in our reductions lie in P. In particular, the elements of S and the coefficients of the inequalities defining P can be restricted to have logarithmic bit-length.
Date issued
2019-07Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer ScienceJournal
Theoretical Computer Science
Publisher
Elsevier BV
Citation
Jean Cardinal et al. “Reconfiguration of satisfying assignments and subset sums: Easy to find, hard to connect.” Theoretical Computer Science, 806 (July 2019): 332-343 © 2019 The Author(s)
Version: Original manuscript
ISSN
0304-3975