Exact Max 2-Sat: Easier and Faster

  • Authors:
  • Martin Fürer;Shiva Prasad Kasiviswanathan

  • Affiliations:
  • Computer Science and Engineering, Pennsylvania State University,;Computer Science and Engineering, Pennsylvania State University,

  • Venue:
  • SOFSEM '07 Proceedings of the 33rd conference on Current Trends in Theory and Practice of Computer Science
  • Year:
  • 2007

Quantified Score

Hi-index 0.00

Visualization

Abstract

Prior algorithms known for exactly solving Max 2-Satimprove upon the trivial upper bound only for very sparse instances. We present new algorithms for exactly solving (in fact, counting) weighted Max 2-Satinstances. One of them has a good performance if the underlying constraint graph has a small separator decomposition, another has a slightly improved worst case performance. For a 2-Satinstance Fwith nvariables, the worst case running time is $\tilde{O}(2^{(1-1/(\tilde{d}(F)-1))n})$, where $\tilde{d}(F)$ is the average degree in the constraint graph defined by F.We use strict 茂戮驴-gadgets introduced by Trevisan, Sorkin, Sudan, and Williamson to get the same upper bounds for problems like Max3-Satand Max Cut. We also introduce a notion of strict (茂戮驴,β)-gadget to provide a framework that allows composition of gadgets. This framework allows us to obtain the same upper bounds for Maxk-Satand Maxk-Lin-2.