Approximately Counting Up To Four ( Extended
نویسندگان
چکیده
We present a fully-polynomial scheme to approximate the number of independent sets in graphs with maximum degree four. In general, for graphs with maximum degree 4, the scheme approximates a weighted sum of independent sets. The weight of each independent set is expressed in terms of a positive parameter 1 3 , where the weight of independent set S is jSj. We also prove complementary hardness of approximation results, which show that it is hard to approximate the weighted sum for values of > c for some constant c > 0.
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