2017/06/30 by Erik D. Demaine, Mikhail Rudoy, Demaine, Erik D. +1 · 1 citation
Computer Science · #Interconnection Networks and Systems #Advanced Graph Theory Research #Complexity and Algorithms in Graphs
paper · pdf · doi:10.48550/arxiv.1706.10046
In 2007, Arkin et al. initiated a systematic study of the complexity of the\nHamiltonian cycle problem on square, triangular, or hexagonal grid graphs,\nrestricted to polygonal, thin, superthin, degree-bounded, or solid grid graphs.\nThey solved many combinations of these problems, proving them either\npolynomially solvable or NP-complete, but left three combinations open. In this\npaper, we prove two of these unsolved combinations to be NP-complete:\nHamiltonicity of Square Polygonal Grid Graphs and Hamiltonicity of Hexagonal\nThin Grid Graphs. We also consider a new restriction, where the grid graph is\nboth thin and polygonal, and prove that Hamiltonicity then becomes polynomially\nsolvable for square, triangular, and hexagonal grid graphs.\n