5. Hash Tree (15 Marks) a) Suppose we have 20 candidate itemsets of length 3: 125), (127), (145), (246). (25 8, (268), (278), (35 6, (3 6 73, (3 68). (369, 1389), (45 8), (468), (478, (489). (5 69). (5 89, 6 78), 679) Please generate a hash tree with max leaf size 2. The hash function is shown in the figure below (6 marks) Hash Function 1,4,7 3,6,9 2,5,8 b) Given a transaction that contains items (1,2, 4, 6, 7, 8,93, Compared to the nave comparison (20 comparisons), how many comparisons are saved after using the hash tree which you generate above? (4 marks) e) Explain what kinds of factors can affect the efficiency of Apriori Algorithm? Why using hash method can improve the Apriori Algorithm