Isomorphism problems and groups of automorphisms for Ore extensions $K[x][y;f\frac{d}{dx}]$ (prime characteristic)

Let $\mathrm{\Lambda }(f)=K[x][y;f\frac{d}{dx}]$ be an Ore extension of a polynomial algebra $K[x]$ over an arbitrary field $K$ of characteristic $p>0$ where $f\in K[x]$. For each polynomial $f$, the automorphism group of the algebras $\mathrm{\Lambda }(f)$ is explicitly described. The automorphism group ${\rm Aut}_K(\L (f))=S\rtimes G_f$ is a semidirect product of two explicit groups where $G_f$ is the {\em eigengroup} of the polynomial $f$ (the set of all automorphisms of $K[x]$ such that $f$ is their common eigenvector). For each polynomial $f$, the eigengroup $G_f$ is explicitly described. It is proven that every subgroup of ${\mathrm{A}\mathrm{u}\mathrm{t}}_K(K[x])$ is the eigengroup of a polynomial. It is proven that the Krull and global dimensions of the algebra $\mathrm{\Lambda }(f)$ are 2. The prime, completely prime, primitive and maximal ideals of the algebra $\mathrm{\Lambda }(f)$ are classified.