The domination number of Cartesian product of two directed paths

In this paper, we conclude the calculation of the domination number of all \(n\times m\) grid graphs. Indeed, we prove Chang's conjecture saying that for every \(16\le n\le m\), \(\gamma(G_{n,m})=\lfloor\frac{(n+2)(m+2)}{5}\rfloor -4\).