Blar i Bergen Open Research Archive på forfatter "Lokshtanov, Daniel"

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    • A (2 + ε)-Factor Approximation Algorithm for Split Vertex Deletion 

      Lokshtanov, Daniel; Misra, Pranabendu; Panolan, Fahad; Philip, Geevarghese; Saurabh, Saket (Journal article; Peer reviewed, 2020)
      In the Split Vertex Deletion (SVD) problem, the input is an n-vertex undirected graph G and a weight function w: V(G) → ℕ, and the objective is to find a minimum weight subset S of vertices such that G-S is a split graph ...

    • b-Coloring Parameterized by Clique-Width 

      Jaffke, Lars; Lima, Paloma Thome de; Lokshtanov, Daniel (Journal article; Peer reviewed, 2021)
      We provide a polynomial-time algorithm for b-Coloring on graphs of constant clique-width. This unifies and extends nearly all previously known polynomial-time results on graph classes, and answers open questions posed by ...

    • b-Coloring Parameterized by Clique-Width 

      Jaffke, Lars; Lima, Paloma T.; Lokshtanov, Daniel (Journal article; Peer reviewed, 2023)
      We provide a polynomial-time algorithm for b- Coloring on graphs of constant clique-width. This unifies and extends nearly all previously known polynomial time results on graph classes, and answers open questions posed by ...

    • Balanced judicious bipartition is fixed-parameter tractable 

      Lokshtanov, Daniel; Saurabh, Saket; Sharma, Roohani; Zehavi, Meirav (Journal article; Peer reviewed, 2019)
      The family of judicious partitioning problems, introduced by Bollobás and Scott to the field of extremal combinatorics, has been extensively studied from a structural point of view for over two decades. This rich realm of ...

    • Bidimensionality and Kernels 

      Fomin, Fedor; Lokshtanov, Daniel; Saurabh, Saket; Thilikos, Dimitrios (Journal article; Peer reviewed, 2020)
      Bidimensionality theory was introduced by [E. D. Demaine et al., J. ACM, 52 (2005), pp. 866--893] as a tool to obtain subexponential time parameterized algorithms on H-minor-free graphs. In [E. D. Demaine and M. Hajiaghayi, ...

    • Bisection of Bounded Treewidth Graphs by Convolutions 

      Eiben, Eduard; Lokshtanov, Daniel; Mouawad, Amer E. (Journal article; Peer reviewed, 2019)
      In the Bisection problem, we are given as input an edge-weighted graph G. The task is to find a partition of V(G) into two parts A and B such that ||A| - |B|| <= 1 and the sum of the weights of the edges with one endpoint ...

    • Covering Vectors by Spaces in Perturbed Graphic Matroids and Their Duals 

      Fomin, Fedor; Golovach, Petr; Lokshtanov, Daniel; Saurabh, Saket; Zehavi, Meirav (Peer reviewed; Journal article, 2019)
      Perturbed graphic matroids are binary matroids that can be obtained from a graphic matroid by adding a noise of small rank. More precisely, an r-rank perturbed graphic matroid M is a binary matroid that can be represented ...

    • Decomposition of map graphs with applications 

      Fomin, Fedor; Lokshtanov, Daniel; Panolan, Fahad; Saurabh, Saket; Zehavi, Meirav (Peer reviewed; Journal article, 2019)

    • ETH-tight algorithms for long path and cycle on unit disk graphs 

      Fomin, Fedor; Lokshtanov, Daniel; Panolan, Fahad; Saurabh, Saket; Zehavi, Meirav (Journal article; Peer reviewed, 2020)
      We present an algorithm for the extensively studied Long Path and Long Cycle problems on unit disk graphs that runs in time 2O(√k)(n + m). Under the Exponential Time Hypothesis, Long Path and Long Cycle on unit disk graphs ...

    • Fault tolerant subgraphs with applications in kernelization 

      Lochet, William; Lokshtanov, Daniel; Misra, Pranabendu; Saurabh, Saket; Sharma, Roohani; Zehavi, Meirav (Journal article; Peer reviewed, 2020)
      In the past decade, the design of fault tolerant data structures for networks has become a central topic of research. Particular attention has been given to the construction of a subgraph H of a given digraph D with as ...

    • Fixed Parameter Set Splitting, Linear Kernel and Improved Running Time 

      Lokshtanov, Daniel; Sloper, Christian (Chapter, 2005)

    • Going Far from Degeneracy 

      Fomin, Fedor; Golovach, Petr; Lokshtanov, Daniel; Panolan, Fahad; Saurabh, Saket; Zehavi, Meirav (Journal article; Peer reviewed, 2020)
      An undirected graph $G$ is $d$-degenerate if every subgraph of $G$ has a vertex of degree at most $d$. By the classical theorem of Erdös and Gallai from 1959, every graph of degeneracy $d>1$ contains a cycle of length at ...

    • Going Far From Degeneracy 

      Fomin, Fedor; Golovach, Petr; Lokshtanov, Daniel; Panolan, Fahad; Saurabh, Saket; Zehavi, Meirav (Peer reviewed; Journal article, 2019-09-06)
      An undirected graph G is d-degenerate if every subgraph of G has a vertex of degree at most d. By the classical theorem of Erd\H{o}s and Gallai from 1959, every graph of degeneracy d>1 contains a cycle of length at least ...

    • Kernel(s) for Problems with No Kernel: On Out-Trees with Many Leaves 

      Fernau, Henning; Fomin, Fedor; Lokshtanov, Daniel; Raible, Daniel; Saurabh, Saket; Villanger, Yngve (Peer reviewed; Journal article, 2009)
      The {\sc \(k\)-Leaf Out-Branching} problem is to find an out-branching, that is a rooted oriented spanning tree, with at least \(k\) leaves in a given digraph. The problem has recently received much attention from the ...

    • On cutwidth parameterized by vertex cover 

      Cygan, Marek; Lokshtanov, Daniel; Pilipczuk, Marcin; Pilipczuk, Michal Pawel; Saurabh, Saket (Peer reviewed; Journal article, 2014-04)
      We study the CUTWIDTH problem, where the input is a graph G, and the objective is find a linear layout of the vertices that minimizes the maximum number of edges intersected by any vertical line inserted between two ...

    • Packing cycles faster than Erdos-Posa 

      Lokshtanov, Daniel; Mouawad, Amer E.; Saurabh, Saket; Zehavi, Meirav (Journal article; Peer reviewed, 2019)
      The Cycle Packing problem asks whether a given undirected graph $G=(V,E)$ contains $k$ vertex-disjoint cycles. Since the publication of the classic Erdös--Pósa theorem in 1965, this problem received significant attention ...

    • Parameterization Above a Multiplicative Guarantee 

      Fomin, Fedor; Golovach, Petr; Lokshtanov, Daniel; Panolan, Fahad; Saurabh, Saket; Zehavi, Meirav (Journal article; Peer reviewed, 2020)
      Parameterization above a guarantee is a successful paradigm in Parameterized Complexity. To the best of our knowledge, all fixed-parameter tractable problems in this paradigm share an additive form defined as follows. Given ...

    • The Parameterized Complexity of Guarding Almost Convex Polygons 

      Agrawal, Akanksha; Knudsen, Kristine Vitting Klinkby; Lokshtanov, Daniel; Saurabh, Saket; Zehavi, Meirav (Journal article; Peer reviewed, 2020)
      The Art Gallery problem is a fundamental visibility problem in Computational Geometry. The input consists of a simple polygon P, (possibly infinite) sets G and C of points within P, and an integer k; the task is to decide ...

    • Parameterized Single-Exponential Time Polynomial Space Algorithm for Steiner Tree 

      Fomin, Fedor; Kaski, Petteri; Lokshtanov, Daniel; Panolan, Fahad; Saurabh, Saket (Peer reviewed; Journal article, 2019)
      In the Steiner Tree problem, we are given as input a connected \(n\)-vertex graph with edge weights in \(\{1,2,\ldots,W\}\), and a set of \(k\) terminal vertices. Our task is to compute a minimum-weight tree that contains ...

    • Path contraction faster than $2^n$ 

      Agrawal, Akanksha; Fomin, Fedor; Lokshtanov, Daniel; Saurabh, Saket; Tale, Prafullkumar (Journal article; Peer reviewed, 2020)
      A graph $G$ is contractible to a graph $H$ if there is a set $X \subseteq E(G)$, such that $G/X$ is isomorphic to $H$. Here, $G/X$ is the graph obtained from $G$ by contracting all the edges in $X$. For a family of graphs ...