[leetcode 78] 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],
[]
]

class Solution {
public:
vector<vector<int> > subsets(vector<int> &S) {
sort(S.begin(), S.end());
vector<vector<int> > res;
vector<int> path;
dfs(S, 0, path, res);
return res;

}
void dfs(const vector<int> &s, int start, vector<int> &path, vector<vector<int> > &res) {
if (start == s.size()) {
res.push_back(path);
return ;
}
for (int i = start; i < s.size(); i++) {
//dfs(s, i+1, path, res);
path.push_back(s[i]);
dfs(s, i+1, path, res);
path.pop_back();
}
res.push_back(path);
return ;
}
};