A processor needs software interrupt to

Consider an undirected unweighted graph G. Let a breadth-first traversal of G be done starting from a node r. Let d(r, u) and d(r, v) be the lengths of the shortest paths from r to u and v respectively in G. If u is visited before v during the breadth-first traversal, which of the following statements is correct?

How many undirected graphs (not necessarily connected) can be constructed out of a given set V = { v₁,v₂,........,v_n } of n vertices?

Consider a schema $$R(A,B,C,D)$$ and functional dependencies $$A \to B\,\,$$ and $$C \to D\,\,$$. Then the decomposition of $$R$$ into $${R_1}\left( {AB} \right)$$ and $${R_2}\left( {CD} \right)$$ is