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],
[]
]
采用递归,取当前元素,或者不取当前元素。
class Solution { public: vector<vector<int> > subsets(vector<int> &S) { vector<vector<int> > result; vector<int> tmp; sort(S.begin(),S.end()); getSubset(result,S,,tmp); return result; } void getSubset(vector<vector<int> > &result,vector<int> &S,int index,vector<int> tmp) { if(index==S.size()) { result.push_back(tmp); return; } getSubset(result,S,index+,tmp); tmp.push_back(S[index]); getSubset(result,S,index+,tmp); } };