Parameterized Complexity of Conflict-free Graph Coloring WADS 2019 Hans L. Bodlaender 1, Sudeshna Kolay 2, and Astrid Pieterse 3 1 Utrecht University, The Netherlands 2 Ben Gurion University of Negev, Israel 3 Eindhoven University of Technology, The Netherlands
Conflict-free graph coloring • z y u v w x
CNCF-Coloring • 2 u v w y x
CNCF-Coloring • 2 2 w u v x y
CNCF-Coloring • 2 2 2 u v w y x
CNCF-Coloring • 2 2
CNCF-Coloring • 2 2 k Observation Any proper coloring is a CNCF-Coloring • Each vertex is the uniquely colored vertex in its closed neighborhood
Background •
Combinatorial results • … …
Background •
Algorithmic results •
Kernelization results • Efficie nt Small bound Corre c t
A general reduction rule
Reducing number of twins • s
Correctness • s s
Correctness • s s
Effectiveness •
Polynomial kernel for 2 -CNCF-Coloring Parameterized by Vertex Cover size