Leetcode 78. Subsets (Medium) (cpp)

/*

78. Subsets (Medium)

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

Note: The solution set must not contain duplicate subsets.

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

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

*/
class Solution {
public:
vector<vector<int>> subsets(vector<int>& nums) {
vector<vector<int>> res;
vector<int> res_sub;
res.push_back(res_sub);
generate(nums, 0, res, res_sub);
return res;
}
void generate(vector<int>& nums, int start, vector<vector<int>>& res, vector<int>& res_sub) {
for (int i = start; i < nums.size(); i++) {
res_sub.push_back(nums[i]);
res.push_back(res_sub);
generate(nums, i + 1, res, res_sub);
res_sub.pop_back();
}
}
};