Abstract
This paper explores computational methods for solving the Longest Vector Problem (LVP) and Closest Vector Problem (CVP) in \(p\) -adic fields. Leveraging the non-Archimedean property of \(p\) -adic norms, we propose a polynomial time algorithm to compute orthogonal bases for \(p\) -adic lattices when the \(p\) -adic field is given by a minimal polynomial. The method utilizes the structure of maximal orders and \(p\) -radicals in extension fields of \(\mathbb{Q}_{p}\) to efficiently construct uniformizers and residue field bases, enabling rapid solutions for the LVP and CVP. In addition, we introduce the characterization of norms on vector spaces over \(\mathbb{Q}_p\) .