Feedback vertex sets and disjoint cycles in planar (di)graphs

We present new fixed parameter algorithms for feedback vertex set and disjoint cycles on planar graphs. We give an $O(c^{\sqrt{k}} + n)$ algorithm for $k$-feedback vertex set and an $O(c^{\sqrt{k}} n)$ algorithm for $k$-disjoint cycles on planar graphs. CitationManuscript 4 July, 2001.ArticleDownload View PDF

Kernels in planar digraphs

A set $S$ of vertices in a digraph $D=(V,A)$ is a kernel if $S$ is independent and every vertex in $V-S$ has an out-neighbour in $S$. We show that there exists an $O(3^{\delta \sqrt{k}} n)$~% \footnote{Throughout this paper the constants $\delta$ and $c$ are the same as the comparative constants mentioned in~\cite{kn:alber}.} algorithm to check … Read more