<p>You are given an array <code>nums</code> of positive integers and a <strong>positive</strong> integer <code>k</code>.</p>

<p>A subset of <code>nums</code> is <strong>beautiful</strong> if it does not contain two integers with an absolute difference equal to <code>k</code>.</p>

<p>Return <em>the number of <strong>non-empty beautiful </strong>subsets of the array</em> <code>nums</code>.</p>

<p>A <strong>subset</strong> of <code>nums</code> is an array that can be obtained by deleting some (possibly none) elements from <code>nums</code>. Two subsets are different if and only if the chosen indices to delete are different.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [2,4,6], k = 2
<strong>Output:</strong> 4
<strong>Explanation:</strong> The beautiful subsets of the array nums are: [2], [4], [6], [2, 6].
It can be proved that there are only 4 beautiful subsets in the array [2,4,6].
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [1], k = 1
<strong>Output:</strong> 1
<strong>Explanation:</strong> The beautiful subset of the array nums is [1].
It can be proved that there is only 1 beautiful subset in the array [1].
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 20</code></li>
	<li><code>1 &lt;= nums[i], k &lt;= 1000</code></li>
</ul>

class Solution {
private:

    void subsets(vector<vector<int> >& res, vector<int>& curr, vector<int>& nums, int k, int idx){


            for(int i=idx ;i<nums.size() ;i++){

               bool isvalid = true;

               for(int num : curr){
                if(abs(num - nums[i]) == k){
                    isvalid = false;
                    break;

                }
               }

               if(isvalid){
                curr.push_back(nums[i]);
                res.push_back(curr);
                subsets(res, curr, nums,k , i+1);
                curr.pop_back();

               }
            }
    }

public:
    int beautifulSubsets(vector<int>& nums, int k) {
        
        vector<vector<int> > res;
        vector<int> curr;

        subsets(res, curr, nums, k , 0);

        return res.size();
    }
};
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