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], [] ]
void sub(vector<int> s, int index, vector<int> &path, vector<vector<int>> &solution)
{
if(index == s.size()){solution.push_back(path);return;}
sub(s,index+1,path,solution);
path.push_back(s[index]);
sub(s,index+1,path,solution);
path.pop_back();
}
vector<vector<int>> subsets(vector<int> &S) {
// Note: The Solution object is instantiated only once.
vector<vector<int>> solution;
vector<int> path;
sort(S.begin(),S.end());
sub(S,0,path,solution);
return solution;
}