Algorithm/randomalg: random algorithm realized

Signed-off-by: Artem Plakunov <artacc@lvk.cs.msu.su>
Algorithm/ants: performance fix

If a link can't be assigned becuase request elements don't exist in the
path, don't assign other links and go to the next request immediately

Signed-off-by: Artem Plakunov <artacc@lvk.cs.msu.su>