It is well known that every finite Abelian group $G$ can be represented as a product of cyclic groups: $G=G_1\times G_2\times\cdots G_t$, where each $G_i$ is a cyclic group of size $p^j$ for some prime $p$ and integer $j\ge 1$. If $a_i$ is the generator of the cyclic group of ... more >>>

We introduce the notion of width bounded geometric separator, develop the techniques for its existence as well as algorithm, and apply it to obtain a $2^{O(\sqrt{n})}$ time exact algorithm for the disk covering problem, which seeks to determine the minimal number of fixed size disks to cover $n$ points on ... more >>>