Let G = (V,E) be an undirected graph. A set F ⊆ E of edges is called a feedback-edge set if every cycle of G has at least one edge in F.
(a) Suppose that G is unweighted. Design an efficient algorithm to find a minimum-size feedback-edge set.
(b) Suppose that G is a weighted undirected graph with positive edge weights. Design an efficient algorithm to find a minimum-weight feedback-edge set.