(a) Find the depth-first spanning tree for the graph shown in Fig. 11.72(a) if the order of the vertices is given as
(i) a, b, c, d, e, f, g, h;
(ii) h, g, f, e, d, c, b, a;
(iii) a, b, c, d, h, g, f, e.
(b) Repeat part (a) for the graph shown in Fig. 11.85(i).