Is it possible to find the complexity, e.g., O(n) etc., of non closed form solutions

[wajahat]

Hi all,

I want to find the complexity of problems with no closed form solution. Is it possible?

For example, finding the intersection area of N circles has a non closed form solution. It is solved using monte carlo methods.
Is possible to find the complexity of solution. With complexity i mean O(N) expression.

I can run different simulations and record the simulation time for different number of circles.
Is it possible to calculate this complexity expression from these simulation times? As i can't run simulation for every N.

regards
wajahat