activity
20152025
collaborators

12 papers

math.CO2025

-Colorability of Planar Graphs Excluding -, -, and -Cycles

Pongpat Sittitrai, Wannapol Pimpasalee, Kittikorn Nakprasit

A defective -coloring is a coloring on the vertices of a graph using colors such that adjacent vertices may share the same color. A -\emph{coloring} o…

math.CO2022

Partitioning planar graphs without 4-cycles and 6-cycles into a forest and a disjoint union of paths

Pongpat Sittitrai, Kittikorn Nakprasit

In this paper, we show that every planar graph without -cycles and -cycles has a partition of its vertex set into two sets, where one set induces a forest, and the other indu…

math.CO2019

Generalization of some results on list coloring and DP-coloring

Keaitsuda Maneeruk Nakprasit, Kittikorn Nakprasit

In this work, we introduce DPG-coloring using the concepts of DP-coloring and variable degeneracy to modify the proofs on the following papers: (i) DP-3-coloring of planar graphs w…

math.CO2019

Planar graphs without pairwise adjacent 3-,4-,5-, and 6-cycle are 4-choosable

Pongpat Sittitrai, Kittikorn Nakprasit

Xu and Wu proved that if every 5-cycle of a planar graph G is not simultaneously adjacent to 3-cycles and 4-cycles, then G is 4-choosable. In this paper, we improve this result as…

math.CO2018

Analogue of DP-coloring on variable degeneracy and its applications on list vertex-arboricity and DP-coloring

Pongpat Sittitrai, Kittikorn Nakprasit

In \cite{listnoC3adjC4}), Borodin and Ivanova proved that every planar graph without -cycles adjacent to -cycle is list vertex--aborable. In fact, they proved a more gener…

math.CO2018

Sufficient conditions on planar graphs to have a relaxed DP--colorability

Pongpat Sittitrai, Kittikorn Nakprasit

It is known that DP-coloring is a generalization of a list coloring in simple graphs and many results in list coloring can be generalized in those of DP-coloring. In this work, we…