(Hamiltonian cycle) The Hamiltonian path algorithm is implemented in Supplement VI.E. Add the following getHamiltonianCycle method in the Graph interface and implement it in the AbstractGraph class:

(Hamiltonian cycle) The Hamiltonian path algorithm is implemented in Supplement VI.E. Add the following getHamiltonianCycle method in the Graph interface and implement it in the AbstractGraph class:

/** Return a Hamiltonian cycle 
* Return null if the graph doesn't contain a Hamiltonian cycle */
public List<Integer> getHamiltonianCycle()