Approximated Vertex Cover for Graphs with Perfect Matchings
نویسندگان
چکیده
Chen and Kanj considered the V C problem for graphs with perfect matchings (VC-PM). They showed that: (i) There is a reduction from general V C to VC-PM, which guarantees that if one can achieve an approximation factor of less than two for VC-PM, then one can do so for general V C as well. (ii) There is an algorithm for VC-PM whose approximation factor is given as 1.069 + 0.069d where d is the average degree of the given graph. In this paper we improve (ii). Namely we give a new VC-PM algorithm which greatly outperforms the above one and its approximation factor is roughly 2− 6.74 d+6.28 . Our algorithm also works for graphs with “large” matchings, although its approximation factor is degenerated. key words: approximation algorithm, vertex cover, perfect matching, MAX-2SAT
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