# Problem 42

#### Description

This problem was asked by Google.

Given a list of integers S and a target number k, write a function that returns a subset of S that adds up to k. If such a subset cannot be made, then return null.

Integers can appear more than once in the list. You may assume all numbers in the list are positive.

For example, given `S = [12, 1, 61, 5, 9, 2]`

and `k = 24`

, return `[12, 9, 2, 1]`

since it sums up to `24`

.