## The problem

Start with a the set of positive integers 1, 2, 3, ..., N. Call that set A. Given a number 'n' satisfying 1 <= n <= N print out a set of all unique subsets of A containing n elements.

Your output should look something like this:

- N = 4 and n = 3:
- Input = Set a = [1,2,3,4], int n = 3
- Output = Set x = [ [1, 2, 3], [1, 2, 4], [1, 3, 4], [2, 3, 4] ]

## Breaking it down

This program was written to use Guava Set utility powerSet method which returns a set of all possible subsets of a set. For example, powerSet(ImmutableSet.of(2, 3)) returns the set {{}, {2}, {3}, {2, 3}} . To satisfy the 'n' the collection must be filtered based on the sub collection.

### Create method

### Running the program

## Output

## Level Up

- Is this the most efficient way to generate combinations, if not what could be done to improve it?
- Determine other approaches could be written to solve the problem