Some inverse results of sumsets

Abstract: Let $h\geq 2$ and $A={a_0,a_1,\ldots,a_{k-1}}$ be a finite set of integers. It is well-known that $\left|hA\right|=hk-h+1$ if and only if $A$ is a $k$-term arithmetic progression. In this paper, we give some nontrivial inverse results of the sets $A$ with some extrema the cardinalities of $hA$.