491. Leetcode solution in cpp

class Solution {
 public:
  vector<vector<int>> findSubsequences(vector<int>& nums) {
    vector<vector<int>> ans;
    dfs(nums, 0, {}, ans);
    return ans;
  }

 private:
  void dfs(const vector<int>& nums, int s, vector<int>&& path,
           vector<vector<int>>& ans) {
    if (path.size() > 1)
      ans.push_back(path);

    unordered_set<int> used;

    for (int i = s; i < nums.size(); ++i) {
      if (used.count(nums[i]))
        continue;
      if (path.empty() || nums[i] >= path.back()) {
        used.insert(nums[i]);
        path.push_back(nums[i]);
        dfs(nums, i + 1, move(path), ans);
        path.pop_back();
      }
    }
  }
};

leetcode

challenge

Here is the link for the problem:
https://leetcode.com/problems/non-decreasing-subsequences/