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], [] ]
C++实现代码:
#include<iostream> #include<vector> #include<set> #include<algorithm> using namespace std; class Solution { public: vector<vector<int> > subsets(vector<int> &S) { if(S.empty()) return vector<vector<int>>(); sort(S.begin(),S.end()); int n=1<<S.size(); int i=0; vector<vector<int> > ret; while(i<n) { vector<int> temp; int index=0; int j=i; while(j>0) { if(j&1) temp.push_back(S[index]); j=j>>1; index++; } ret.push_back(temp); i++; } return ret; } }; int main() { Solution s; vector<int> vec= {2,1,3}; vector<vector<int> > result=s.subsets(vec); for(auto a:result) { for(auto v:a) cout<<v<<" "; cout<<endl; } }
运行结果: