NEW APPROXIMATION ALGORITHMS FOR MAX 2SAT AND MAX DICUT

New Approximation Algorithms for Max 2sat and Max Dicut

We propose a 0.935-approximation algorithm for MAX 2SAT and a 0.863-approximation algorithm for MAX DICUT. The approximation ratios improve upon the recent results of Zwick, which are equal to 0.93109 and 0.8596434254 respectively. Also proposed are derandomized versions of the same approximation ratios. We note that these approximation ratios are obtained by numerical computation rather than t...

0.863-Approximation Algorithm for MAX DICUT

Improved Approximation Algorithms for Max-2SAT with Cardinality Constraint

The optimization problem Max-2SAT-CC is Max-2SAT with the additional cardinality constraint that the value one may be assigned to at most K variables. We present an approximation algorithm with polynomial running time for Max-2SAT-CC. This algorithm achieves, for any > 0, approximation ratio 6+3·e 16+2·e − ≈ 0.6603. Furthermore, we present a greedy algorithm with running time O(N logN) and appr...

Aproximating the Value of Two Prover Proof Systems, With Applications to MAX 2SAT and MAX DICUT

It is well known that two prover proof systems are a convenient tool for establishing hardness of approximation results. In this paper, we show that two prover proof systems are also convenient starting points for establishing easiness of approximation results. Our approach combines the Feige-Lovv asz (STOC92) semideenite programming relaxation of one-round two-prover proof systems, together wi...

0.935-Approximation Randomized Algorithm for MAX 2SAT and its Derandomization

In this paper, we propose 0.935-approximation algorithm for MAX 2SAT. The approximation ratio is better than the previously known result by Zwick, which is equal to 0.93109. The algorithm solves the SDP relaxation problem proposed by Goemans and Williamson for the first time. We do not use the ‘rotation’ technique proposed by Feige and Goemans. We improve the approximation ratio by using hyperp...