Maximal 2-Dimensional Binary Words of Bounded Degree
摘要
Let \(d \in \{0, 1, 2, 3, 4\}\) and W be a 2-dimensional word of dimensions \(h \times w\) on the binary alphabet \(\{\square,\blacksquare \}\) , where \(h,w \in \mathbb {Z}_{>0}\) . Assume that each occurrence of the letter \(\blacksquare \) in W is adjacent to at most d letters \(\blacksquare \) and let \(|W|_{\blacksquare}\) be the number of letters \(\blacksquare \) in W. We provide an exact formula for the maximum value of \(|W|_{\blacksquare}\) for fixed (h, w). As a byproduct, we deduce an upper bound on the length of maximum snake polyominoes contained in a \(h \times w\) rectangle.