How to express the data structure in the pesudocode of your algorithm If I stored the output for my algorithm as a data structure as a cell array. How can I express that when I am writing the pseudocode for my algorithm. 

For example, I have a set of $n$ values like {2,4,6} and for each value, I run the algorithm and output a matrix. 

I want to express in the pseudocode of my algorithm how I stored the matrix for each value and output these values and the matrices corresponding to it.
There are no set rules, but these type of details are sometimes omitted from the pseudocode listing. You might see something like

ALGORITHM(S, n):
For i = 1 to n do
   S = ADD(S, i)
EndFor


Then followed by something like "... the algorithm performs $\Theta(n)$ units of work assuming that the set $S$ is implemented as blah so that the addition of an element ADD(S,i) runs in blah time ..."