Approximating rank-width and clique-width quickly
Approximating rank-width and clique-width quickly
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快速近似排名宽度和派系宽度
DOI:
10.1145/1435375.1435385
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发表时间:
2005
期刊:
影响因子:
--
通讯作者:
Sang
中科院分区:
文献类型:
--
作者:
Sang
Rank-width was defined by Oum and Seymour [2006] to investigate clique-width. They constructed an algorithm that either outputs a rank-decomposition of width at most <i>f</i>(<i>k</i>) for some function <i>f</i> or confirms that rank-width is larger than <i>k</i> in time <i>O</i>(|<i>V</i>|<sup>9</sup>log |<i>V</i>|) for an input graph <i>G</i> = (<i>V</i>,<i>E</i>) and a fixed <i>k</i>. We develop three separate algorithms of this kind with faster running time. We construct an <i>O</i>(|<i>V</i>|<sup>4</sup>)-time algorithm with <i>f</i>(<i>k</i>) = 3<i>k</i> + 1 by constructing a subroutine for the previous algorithm; we avoid generic algorithms minimizing submodular functions used by Oum and Seymour. Another one is an <i>O</i>(|<i>V</i>|<sup>3</sup>)-time algorithm with <i>f</i>(<i>k</i>) = 24<i>k</i>, achieved by giving a reduction from graphs to binary matroids; then we use an approximation algorithm for matroid branch-width by Hliněný [2005]. Finally we construct an <i>O</i>(|<i>V</i>|<sup>3</sup>)-time algorithm with <i>f</i>(<i>k</i>) = 3<i>k</i> − 1 by combining the ideas of the two previously cited papers.