Let l be the number of edges in a longest cycle containing a given vertex v in an undirected graph. We show how to find a cycle through v of length (Ω(√ log l, log log l)) in polynomial time. This implies the same bound for the longest cycle, longest vw-path and longest path. The previous best bound for longest path is length Ω((log l )2/, log log l) due to Bjorklund and Husfeldt. Our approach, which builds on Bjorklund and Husfeldt's, uses cycles to enlarge cycles. This self-reducibility allows the approximation method to be iterated.
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机译:设l为最长周期中无向图中包含给定顶点 v I>的边数。我们展示了如何在多项式时间内通过长度(Ω(√log l,log log l))的 v I>找到一个循环。这意味着最长的循环,最长的 vw I>路径和最长的路径具有相同的界限。由于Bjorklund和Husfeldt的原因,最长路径的先前最佳界限是长度Ω((log l) 2 SUP> /,log log 1)。我们基于Bjorklund和Husfeldt的方法,使用周期来扩大周期。这种自归约性允许迭代近似方法。
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