Browsing Waterloo Research by Subject "colouring"
Now showing items 1-6 of 6
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Approximately Coloring Graphs Without Long Induced Paths
(Springer Nature, 2017)It is an open problem whether the 3-coloring problem can be solved in polynomial time in the class of graphs that do not contain an induced path on t vertices, for fixed t. We propose an algorithm that, given a 3-colorable ... -
Four-coloring P6-free graphs
(Association for Computing Machinery, 2019)In this paper we present a polynomial time algorithm for the 4-COLORING PROBLEM and the 4-PRECOLORING EXTENSION problem restricted to the class of graphs with no induced six-vertex path, thus proving a conjecture of Huang. ... -
H-colouring Pt-free graphs in subexponential time
(Elsevier, 2019-08-31)A graph is called Pt-free if it does not contain the path on t vertices as an induced subgraph. Let H be a multigraph with the property that any two distinct vertices share at most one common neighbour. We show that the ... -
Polynomial bounds for chromatic number II: Excluding a star-forest
(Wiley, 2022-10)The Gyárfás–Sumner conjecture says that for every forest H, there is a function fH such that if G is H-free then x(G) ≤ fH(w(G)) (where x,w are the chromatic number and the clique number of G). Louis Esperet conjectured ... -
Polynomial bounds for chromatic number VII. Disjoint holes.
(Wiley, 2023-05-14)A hole in a graph G is an induced cycle of length at least four, and a k-multihole in G is the union of k pairwise disjoint and nonneighbouring holes. It is well known that if G does not contain any holes then its chromatic ... -
Polynomial bounds for chromatic number VII. Disjoint holes.
(Wiley, 2023-11)A hole in a graph G is an induced cycle of length at least four, and a k-multihole in G is the union of k pairwise disjoint and nonneighbouring holes. It is well know that if G does not contain any holes then its chromatic ...