On identifying codes in the triangular and square grids

It is shown that in the infinite square grid the density of every (r,≤ 2)-identifying code is at least 1/8 and that there exists a sequence Cr of (r,≤ 2)-identifying codes such that the density of Cr tends to 1/8 when r → ∞. In the infinite triangular grid a sequence C′ r of (r,≤ 2)identifying codes is given such that the density of C′ r tends to 0 when r… CONTINUE READING