5G technologies are taking benefit of the Network Function Virtualization to achieve more flexible deployments. This new paradigm allows the resource sharing between operators in federated environments thanks to the decomposition of services into virtual network functions connected together composing a "service function chain". This work proposes algorithms to solve the placement of such chains in federated multi-domain scenarios satisfying imposed restrictions in terms of resource sharing. Algorithms run on top of an implemented simulator for federated scenarios where multiple operators are involved. Two of our proposed solutions reach O(N) running times in certain scenarios. Our results also show that we achieve acceptance ratios very similar to those obtained using a tabu meta-heuristic implementation. This work has been partially supported by the EU H2020 5G Exchange (5GEx) innovation project (grant no. 671636) and by EU H2020 5G-Transformer Project (grant no. 761536).