Indexed variable names, or vector of vectors?

[jling]

@byrnoga

I mean defining a heterogeneous list or a vector of vectors where each of the elements can grow dynamically? (without compromising too much of execution performance)

yes

julia> s = [Int[] for _ = 1:20]; #vector of vector

julia> append!(s[3], 20);

julia> s[2]
Int64[]

julia> s[3]
1-element Vector{Int64}:
 20

or you can use a Dict() with Int as keys and Vector{Int} as values