[1] (8 points) Given an array A = (18, 15, 22, 25, 16, 20, 17, 30, 31). Build the corresponding maxheaps by following the BUILD-MAX-HEAP algorithm. Show the step-by-step tree representation (see page 39~41 of the slides of week07 for an example) when building the maxheaps. You may fill the nodes with their corresponding keys at each step. (4 points) Circle node i at each step. (4 points)
You may not need as many steps as shown in the table below.
(1)
(3)
(2)
(4)