(a) From a computational viewpoint, is it easy or hard to find the chromatic polyno- mial of an arbitrary graph? Explain. (b) Consider the following edge-weighted graph. 9 4 1 11 a 8 7 9 e 10 2, 12 6 b d 4 3 (i) Use the greedy algorithm to find a minimum-weight spanning tree of this graph. What is the weight of such a spanning tree? Show your working. (ii) How would you modify the greedy algorithm to find a maximum-weight span- ning tree? No justification is necessary, but the modification needs to be clearly explained. Activat