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.
1 <= k <= nums.length <= 161 <= nums[i] <= 10^4[1, 4]nums = [4,3,2,3,5,2,1], k = 4truenums = [1,2,3,4], k = 3false