Vertex coloring problem is a well-known NP-Hard problem where the objective is to minimize the number of colors used to color vertices of a graph ensuring that adjacent vertices cannot have same color. In this paper, we first discuss existing mathematical formulations of the problem and then consider two different heuristics, namely HEUR-RA and HEUR-RC, based on Lagrangian relaxation of adjacency and coloring constraints. HEUR-RA does not require solving any optimization problem through execution whereas at each iteration of HEUR-RC another NP-Hard problem, maximal weight stable set problem, is solved. We conduct experiments to observe computational performances of these heuristics. The experiments reveal that although it requires longer running times, HEUR-RC outperforms HEUR-RA since it provides lower optimal gaps as well as upper bound information.
Primary Language | English |
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Journal Section | Engineering Sciences |
Authors | |
Publication Date | June 25, 2020 |
Submission Date | October 2, 2019 |
Acceptance Date | June 15, 2020 |
Published in Issue | Year 2020Volume: 41 Issue: 2 |