Introduction - If you have any usage issues, please Google them yourself
Description: a subset of the problem and given a set of n integers X = (x1, x2, ..., xn) and an integer Y, find the X and Y equal to a subset of subX. For example, if X = (10,20,30,40,50,60) and Y = 60 there are three different length of the solution, they are subY = (10,20,30), (20,40) and (60) use of retrospective method. development tool VS2005