Write a program that uses the decrease-and-conquer algorithm as discussed in class to generate the power set of a set of n unique elements. The power set of a set S is the set of all the subsets of S, including the empty set and S itself. For example, if S is {4, 9, 5}, the power set your program should output is {}, {4}, {9}, {4, 9}, {5}, {4, 5}, {9, 5}, {4, 9, 5}.