Yes, but no.
Please use decimal "ones" or "zeros" when counting in decimal - binary "ones" and "zeros", though technically the same, don't like it very much to be misgendered that way - because they identify as binary :D

Thats so nice and clean - tried similar, but didn't knew you could use a for-loop as a lazy while-loop like that and I
also wasn't sure if bitshift-equals is a legal expression.

why the use of size_t insead of unsigned?

0 is true

== 0 is false

< 0 is true ?

how the loop stops when value == 0? can you explain?

Some like to cast malloc()'s result, some don't. It's a matter of taste, I guess. See e.g. https://en.wikipedia.org/wiki/C_dynamic_memory_allocation#Type_safety

try calloc next time

many probs

I made such a dreadful solution in comparison to this one

if n==0 then result will be a dangling pointer in c.

I think you're right. I think the solution would be to add condition at the beginning that allocates n*sizeof if n>=3 otherwise 3*sizeof.

I think you're right. I think the solution would be to add condition at the beginning that allocates n*sizeof if n>=3 otherwise 3*sizeof.

this should return an error if n = 2 or n = 1

@anaiel signature is an array of size 3 by definition