Enumerate All Member Choices from Distinct Values

### Problem Return every subset of the distinct integers in `nums`, including the empty subset and the full set. Include each choice of members once. The collection may be returned in any order; rearranging the members of a subset does not create a different subset. ```cpp vector<vector<int>> subsets(vector<int>& nums); ``` ### Examples ```text Input: nums = [-2,4] One valid output: [[],[4],[-2,4],[-2]] ``` ```text Input: nums = [7] One valid output: [[7],[]] ``` ### Constraints & Assumptions - `1 <= nums.length <= 10`. - Every entry is between -10 and 10, inclusive, and all entries are distinct. - Return subsets rather than permutations or only subsets of one size. ### Clarifying Questions to Ask - Is the empty subset included? Yes. - Does the returned collection need a prescribed order? No. ```hint Account for every choice Each input element may belong to a subset or be absent. The final collection must represent every member choice exactly once. ``` ### What a Strong Answer Covers - Complete enumeration without duplicate member sets. - The empty and full subsets and a representation that preserves each selected value. - Time and memory costs that include the returned collection. ### Follow-up Questions - How many subsets must be returned for an input of length `n`? - How can a checker compare two correct collections in different orders?