<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 {
public:
    void helper(vector<int> &nums,int k,int &ans,int idx,unordered_map<int,int> &m1){
        if(idx==nums.size()){
            return;
        }
        for(int i=idx;i<nums.size();i++){
            if((m1.find(nums[i]+k)==m1.end() && m1.find(nums[i]-k)==m1.end())){
                m1[nums[i]]++;
                ans++;
                helper(nums,k,ans,i+1,m1);
                m1[nums[i]]--;
                if (m1[nums[i]] == 0) {
                    m1.erase(nums[i]);
                }
            }
        }
    }
    int beautifulSubsets(vector<int>& nums, int k) {
        int ans=0;
        vector<int>v1;
        unordered_map<int,int> m1;
        sort(nums.begin(),nums.end());
        helper(nums,k,ans,0,m1);
        return ans;
    }
};
136802