複選題
38. Trees and graphs are fundamental data structures. Which of the following statements are true?
(A) A weighted graph may bave multiple minimum spanning trees of the same cost.
(B) For two nodes in a graph, there may exist multiple shortest paths of the same length linking the two nodes.
(C) For two nodes in a tree, there may exist multiple shortest paths of the same length linking the two nodes.
(D) For a graph with n nodes and m edges, its minimum spanning tree has at least (n-1) edges.
(E) For a tree with n nodes and m edges, ntm＜2n must hold.