Page 1221 - AP Computer Science A, 7th edition

16. (C) To return the number of elements in the set for Method One requires no more than returning the number of elements in the array. For Method Two, however, the number of cells that contain true must be counted, which requires a test for each of the MAX values. Note that searching for a target value in the set is more efficient for Method Two. For example, to test whether 2 is in the set, simply check if a[2] == true. In Method One, a sequential search must be done, which is less efficient. To print all the elements in Method One, simply loop over the known number of elements and print. Method Two is less efficient because the whole array must be examined: Each cell must be tested for true before printing.