## Abstract

Let π be a family of graphs. In the classical π-Vertex Deletion problem, given a graph G and a positive integer k, the objective is to check whether there exists a subset S of at most k vertices such that G − S is in π. In this paper, we introduce the conflict free version of this classical problem, namely Conflict Free π-Vertex Deletion (CF-π-VD), and study these problems from the viewpoint of classical and parameterized complexity. In the CF-π-VD problem, given two graphs G and H on the same vertex set and a positive integer k, the objective is to determine whether there exists a set S ⊑ V(G), of size at most k, such that G − S is in π and H[S] is edgeless. Initiating a systematic study of these problems is one of the main conceptual contribution of this work. We obtain several results on the conflict free version of several classical problems. Our first result shows that if π is characterized by a finite family of forbidden induced subgraphs then CF-π-VD is Fixed Parameter Tractable (FPT). Furthermore, we obtain improved algorithms for conflict free version of several well studied problems. Next, we show that if π is characterized by a “well-behaved” infinite family of forbidden induced subgraphs, then CF-π-VD is W[1]-hard. Motivated by this hardness result, we consider the parameterized complexity of CF-π-VD when H is restricted to well studied families of graphs. In particular, we show that the conflict free versions of several well-known problems such as Feedback Vertex Set, Odd Cycle Transversal, Chordal Vertex Deletion and Interval Vertex Deletion are FPT when H belongs to the families of d-degenerate graphs and nowhere dense graphs.

Original language | English |
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Title of host publication | Computer Science - Theory and Applications - 13th International Computer Science Symposium in Russia, CSR 2018, Proceedings |

Editors | Vladimir V. Podolskii, Fedor V. Fomin |

Publisher | Springer Verlag |

Pages | 194-206 |

Number of pages | 13 |

ISBN (Print) | 9783319905297 |

DOIs | |

State | Published - 1 Jan 2018 |

Externally published | Yes |

Event | 13th International Computer Science Symposium in Russia, CSR 2018 - Moscow, Russian Federation Duration: 6 Jun 2018 → 10 Jun 2018 |

### Publication series

Name | Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) |
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Volume | 10846 LNCS |

ISSN (Print) | 0302-9743 |

ISSN (Electronic) | 1611-3349 |

### Conference

Conference | 13th International Computer Science Symposium in Russia, CSR 2018 |
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Country/Territory | Russian Federation |

City | Moscow |

Period | 6/06/18 → 10/06/18 |

## Keywords

- Conflict free
- Hereditary properties
- Kernelization
- Parameterized algorithms
- Vertex cover

## ASJC Scopus subject areas

- Theoretical Computer Science
- General Computer Science