LeetCode-Subsets

Given a set of distinct integers, S, return all possible subsets.

Note:

• Elements in a subset must be in non-descending order.
• The solution set must not contain duplicate subsets.

For example,
If S = [1,2,3], a solution is:

[  [3],  [1],  [2],  [1,2,3],  [1,3],  [2,3],  [1,2],  []]

Solution:

Code:

<span style="font-size:14px;">class Solution {public:    void helper(vector<int> &S, int index, const int &length, vector<vector<int> > &results, vector<int> &result) {        for (int i = index; i < length; i++) {            result.push_back(S[i]);            results.push_back(result);            helper(S, i+1, length, results, result);            result.pop_back();        }    }        vector<vector<int> > subsets(vector<int> &S) {        vector<vector<int> > results;        vector<int> result;        results.push_back(result);        int length = S.size();        if (length == 0) return results;        sort(S.begin(), S.end());        helper(S, 0, length, results, result);        return results;    }};</span>