  Every square matrix $A=(a_{uv})\in \mathcal{C}^{n\times n}$ can be
represented as a digraph having $n$ vertices. In the digraph, a block (or
2-connected component) is a maximally connected subdigraph that has no
cut-vertex. The determinant and the permanent of a matrix can be calculated in
terms of the determinant and the permanent of some specific induced subdigraphs
of the blocks in the digraph. Interestingly, these induced subdigraphs are
vertex-disjoint and they partition the digraph. Such partitions of the digraph
are called the $\mathcal{B}$-partitions. In this paper, first, we develop an
algorithm to find the $\mathcal{B}$-partitions. Next, we analyze the
parameterized complexity of matrix determinant and permanent, where, the
parameters are the sizes of blocks and the number of cut-vertices of the
digraph. We give a class of combinations of cut-vertices and block sizes for
which the parametrized complexities beat the state of art complexities of the
determinant and the permanent.
