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], [] ]
Code:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
|
class
Solution {
public :
void
findSub(vector< int > &S, int
&n, int
level, vector< int > &buf, vector<vector< int >> &res){
if (buf.size()==n){
res.push_back(buf);
return ;
}
for ( int
i=level;i<S.size();i++){
buf.push_back(S[i]);
findSub(S,n,i+1,buf,res);
buf.pop_back();
}
}
vector<vector< int > > subsets(vector< int > &S) {
vector<vector< int >> res;
vector< int > buf;
sort(S.begin(),S.end());
for ( int
i=0;i<=S.size();i++)
findSub(S,i,0,buf,res);
return
res;
}
}; |