Given an integer array nums and an integer k, return true if it is possible to divide this array into k non-empty subsets whose sums are all equal.

4 3 2 5 1

3

true

Explanation: It's possible to divide it into 3 subsets (5), (1, 4), (2,3) with equal sums.

1 <= k <= nums.length <= 16

1 <= nums[i] <= 10

The frequency of each element is in the range [1, 4].