Almost optimum $\ell$-covering of ${\mathbb{Z}}_n$

Ke Shi, Chao Xu

A subset $B$ of the ring ${\mathbb{Z}}_n$ is referred to as a $\ell$-covering set if $\{ab(\mathrm{mod}n)|0\le a\le \ell ,b\in B\}={\mathbb{Z}}_n$. We show that there exists a $\ell$-…