Bounds on Greedy Algorithms for MAX SAT

Greedy Algorithms for the Maximum Satisfiability Problem: Simple Algorithms and Inapproximability Bounds

We give a simple, randomized greedy algorithm for the maximum satisfiability problem (MAX SAT) that obtains a 3 4 -approximation in expectation. In contrast to previously known 3 4 -approximation algorithms, our algorithm does not use flows or linear programming. Hence we provide a positive answer to a question posed by Williamson in 1998 on whether such an algorithm exists. Moreover, we show t...

Exact Max 2-Sat: Easier and Faster

Prior algorithms known for exactly solving Max 2-Sat improve upon the trivial upper bound only for very sparse instances. We present new algorithms for exactly solving (in fact, counting) weighted Max 2-Sat instances. 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-Sat inst...

Greedy algorithms for max sat and maximum matching: their power and limitations

On Approximation Algorithms for Hierarchical MAX-SAT

We prove upper and lower bounds on performance guarantees of approximation algorithms for the Hierarchical MAX-SAT (H-MAX-SAT) problem. This problem is representative of a broad class of PSPACE-hard problems involving graphs, Boolean formulas and other structures that are de ned succinctly. Our rst result is that for some constant < 1, it is PSPACE-hard to approximate the function H-MAX-SAT to ...

A Parallel GRASP for MAX-SAT Problems

The weighted maximum satis ability MAX SAT problem is central in mathematical logic computing theory and many indus trial applications In this paper we present a parallel greedy randomized adaptive search procedure GRASP for solving MAX SAT problems Experimental results indicate that almost linear speedup is achieved