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(); } } } };