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    Chapter and Conference Paper

    Circle Graph Isomorphism in Almost Linear Time

    Circle graphs are intersection graphs of chords of a circle. In this paper, we present a new algorithm for the circle graph isomorphism problem running in time ...

    Vít Kalisz, Pavel Klavík, Peter Zeman in Theory and Applications of Models of Computation (2022)

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    Chapter and Conference Paper

    Graph Isomorphism Restricted by Lists

    The complexity of graph isomorphism (GraphIso) is a famous problem in computer science. For graphs G and H, it asks whether they are the same up to a relabeling of vertices. In 1981, Lubiw proved that list restri...

    Pavel Klavík, Dušan Knop, Peter Zeman in Graph-Theoretic Concepts in Computer Science (2020)

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    Article

    On the Classes of Interval Graphs of Limited Nesting and Count of Lengths

    In 1969, Roberts introduced proper and unit interval graphs and proved that these classes are equal. Natural generalizations of unit interval graphs called k-length interval graphs were considered in which the nu...

    Pavel Klavík, Yota Otachi, Jiří Šejnoha in Algorithmica (2019)

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    Article

    Extending Partial Representations of Interval Graphs

    Interval graphs are intersection graphs of closed intervals of the real-line. The well-known computational problem, called recognition, asks whether an input graph G can be represented by closed intervals, i.e., ...

    Pavel Klavík, Jan Kratochvíl, Yota Otachi, Toshiki Saitoh, Tomáš Vyskočil in Algorithmica (2017)

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    Article

    Extending Partial Representations of Proper and Unit Interval Graphs

    The recently introduced problem of extending partial interval representations asks, for an interval graph with some intervals pre-drawn by the input, whether the partial representation can be extended to a rep...

    Pavel Klavík, Jan Kratochvíl, Yota Otachi, Ignaz Rutter, Toshiki Saitoh in Algorithmica (2017)

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    Chapter and Conference Paper

    Cops and Robbers on String Graphs

    The game of cops and robber, introduced by Nowakowski and Winkler in 1983, is played by two players on a graph. One controls k cops and the other a robber. The players alternate and move their pieces to the dista...

    Tomáš Gavenčiak, Przemysław Gordinowicz, Vít Jelínek in Algorithms and Computation (2015)

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    Chapter and Conference Paper

    Minimal Obstructions for Partial Representations of Interval Graphs

    Interval graphs are intersection graphs of closed intervals. A generalization of recognition called partial representation extension was introduced recently. The input gives an interval graph w...

    Pavel Klavík, Maria Saumell in Algorithms and Computation (2014)

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    Chapter and Conference Paper

    Extending Partial Representations of Proper and Unit Interval Graphs

    The recently introduced problem of extending partial interval representations asks, for an interval graph with some intervals pre-drawn by the input, whether the partial representation can be extended to a rep...

    Pavel Klavík, Jan Kratochvíl, Yota Otachi, Ignaz Rutter in Algorithm Theory – SWAT 2014 (2014)

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    Chapter and Conference Paper

    Algorithmic Aspects of Regular Graph Covers with Applications to Planar Graphs

    A graph G covers a graph H if there exists a locally bijective homomorphism from G to H. We deal with regular covers in which this locally bijective homomorphism is prescribed by an action of a su...

    Jiří Fiala, Pavel Klavík, Jan Kratochvíl in Automata, Languages, and Programming (2014)

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    Chapter and Conference Paper

    Bounded Representations of Interval and Proper Interval Graphs

    Klavík et al. [ar**v:1207.6960] recently introduced a generalization of recognition called the bounded representation problem which we study for the classes of interval and proper interval graphs. The input gives...

    Martin Balko, Pavel Klavík, Yota Otachi in Algorithms and Computation (2013)

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    Chapter and Conference Paper

    Cops and Robbers on Intersection Graphs

    The game of cops and robber, introduced by Nowakowski and Winkler in 1983, is played by two players on a graph G, one controlling k cops and the other one robber, all positioned on V ...

    Tomás Gavenčiak, Vít Jelínek, Pavel Klavík, Jan Kratochvíl in Algorithms and Computation (2013)

  12. Chapter and Conference Paper

    Extending Partial Representations of Circle Graphs

    The partial representation extension problem is a recently introduced generalization of the recognition problem. A circle graph is an intersection graph of chords of a circle. We study th...

    Steven Chaplick, Radoslav Fulek, Pavel Klavík in Graph Drawing (2013)

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    Chapter and Conference Paper

    Extending Partial Representations of Function Graphs and Permutation Graphs

    Function graphs are graphs representable by intersections of continuous real-valued functions on the interval [0,1] and are known to be exactly the complements of comparability graphs. As such they are recogni...

    Pavel Klavík, Jan Kratochvíl, Tomasz Krawczyk, Bartosz Walczak in Algorithms – ESA 2012 (2012)

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    Chapter and Conference Paper

    MSOL Restricted Contractibility to Planar Graphs

    We study the computational complexity of graph planarization via edge contraction. The problem Contract asks whether there exists a set S of at most k edges that when contracted produces a planar graph. We give a...

    James Abello, Pavel Klavík, Jan Kratochvíl in Parameterized and Exact Computation (2012)

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    Chapter and Conference Paper

    Extending Partial Representations of Subclasses of Chordal Graphs

    Chordal graphs are intersection graphs of subtrees in a tree. We investigate complexity of the partial representation extension problem for chordal graphs. A partial representation specifies a tree T′ and some pr...

    Pavel Klavík, Jan Kratochvíl, Yota Otachi, Toshiki Saitoh in Algorithms and Computation (2012)

  16. No Access

    Chapter and Conference Paper

    On the Complexity of Planar Covering of Small Graphs

    The problem Cover(H) asks whether an input graph G covers a fixed graph H (i.e., whether there exists a homomorphism G → H which locally preserves the structure of the graphs). Complexity of this problem has been...

    Ondřej Bílka, Jozef Jirásek, Pavel Klavík in Graph-Theoretic Concepts in Computer Scien… (2011)

  17. No Access

    Chapter and Conference Paper

    Extending Partial Representations of Interval Graphs

    We initiate the study of the computational complexity of the question of extending partial representations of geometric intersection graphs. In this paper we consider classes of interval graphs – given a colle...

    Pavel Klavík, Jan Kratochvíl, Tomáš Vyskočil in Theory and Applications of Models of Compu… (2011)

  18. No Access

    Chapter and Conference Paper

    Structural and Complexity Aspects of Line Systems of Graphs

    We study line systems in metric spaces induced by graphs. A line is a subset of vertices defined by a relation of betweenness.

    Jozef Jirásek, Pavel Klavík in Algorithms and Computation (2010)