Sufficient conditions for a interaction to be classified as weak, strong, ...? Let us say I have been given the equation of a interaction/decay/etc. between particles:
$$X+Y\rightarrow A+B$$
Are their any sufficient conditions that we can use to determine the type of interaction this is?
I  know that, for example, if their is a neutrino involved then the interaction is weak.
 A: Life is not so simple, as in all high energy interactions there is a probability of a large number of particles appearing at the main interaction which will subsequently have decays through the weak or electromagnetic interaction. 
If one sees jets of hadrons in the detectors the strong interaction is involved, but the main vertex may be  electromagnetic, as in e+ e- annihilation, for example.


A Feynman diagram demonstrating  an annihilation of an electrons (e–)  and a positron (e+) into a photon (γ) that produces a bottom quark (b) and anti-bottom quark (b) pair, which then radiate gluons (blue).  Fig7 in this link.

The bottom quarks,whose decays are weak,  will appear as hadronic jets which also may well have decays into neutrinos.
Lifetimes and widths of resonances can give an indication, as electromagnetic ones will have narrow widths , weak will have long lifetimes and strong very short ones according to the couplings of the corresponding interactions. But there are also quantum number conservation rules that can spoil the guess: a good example is the width of the J/psi.
So no there is no sufficient condition. The specific interaction that has been measured has to be studied and fitted with the standard model expectations for the primary vertex.
A: I totally agree with anna v's answer. Here I will just give some reasoning that you may use to determine the nature.
Forbidden
If the conservation of $Q$, Lepton number or Baryon number is not obeyed.
Weak interaction
If their are neutrino's involved, or the quantum numbers $S$, $C$ or $\tilde B$ are not conserved then the interaction weak (given that it is not 'forbidden').
Strong interaction
If $S$, $C$ and $\tilde B$ are all be conserved and the interaction consist only of Baryons then it is very likely Strong.
EM
If $S$, $C$ and $\tilde B$ are all be conserved and but the interaction consists of leptons as well as Baryons then it is very likely EM. Furthermore if the interaction has photons then it will be EM.
References
[1] Martin, B.R. and Shaw, G., 2013. Particle physics. John Wiley & Sons.
