ordering vertices according to post-order and pre-order traversals. tree with root vertex d that has a left edge to f, a center edge to b, and a right edge to a. b has a left edge to i, a center edge to h, and a right edge to e. a has a center edge to c. c has a center edge to g. (a) give the order in which the vertices of the tree are visited in a post-order traversal. (b) give the order in which the vertices of the tree are visited in a pre-order traversal.
