Suppose we are given a set of $($non$-$negative$)$ numbers, $S,$ and a number, $n.$ We want to design a

recursive$/$backtracking method, called SUBSETN, that prints all different subsets of $S$ with total sum

of $n($if we add the numbers in a subset they add up to $n).$

For example, SuBSETN$(\{4,2,9,3\},9)$ will print $"423"($in one line$)$ and $"9"($in another line$).$