
You are given an array nums of positive integers and a positive integer k .
A subset of nums is beautiful if it does not contain two integers with an absolute difference equal to k .
Return the number of non-empty beautiful subsets of the array nums .
A subset of nums is an array that can be obtained by deleting some (possibly none) elements from nums . Two subsets are different if and only if the chosen indices to delete are different.
1 <= nums.length <= 181 <= nums[i], k <= 1000