Re: Avoid using "listput()" if possible?

["Ruud H.G. van Tol" <rvtol@isolution.nl>]

On 2024-03-12 09:06, hermann@stamm-wilbrandt.de wrote:
> Yesterday I was happy to have working "SquaresRepresentations(n,k)" 
> using "for(...foreach(...listput(..)))".
> [...]
> I see that "listput()" is definitely needed in some scenarios. 
> Question is, whether using lists should be avoided if possible as 
> above? Without list above looks nicer to me; is a general statement 
> about runtimes with/without list on big inputs possible?

concat() is fine for vectors of short length.

? my(N=2^12, v=[]); for(i=1,N, v=concat([i],v));
cpu time = 119 ms, real time = 120 ms.

? my(N=2^12, v=List()); for(i=1,N, listput(v,i)); Vecrev(v);
cpu time = 3 ms, real time = 3 ms.

-- Ruud