Subsets II
Given a collection of integers that might contain duplicates, 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 = [1,2,2], a solution
is:
[ [2], [1], [1,2,2], [2,2], [1,2], [] ]
算法思想：
递归求解，按照答案要求先要排序
class Solution {
public:
void dfs(vector<int> &S,int start,vector<int> &path,vector<vector<int>> &result){
result.push_back(path);
for(int i=start;i<S.size();i++){
if(i!=start&&S[i]==S[i-1])continue;
path.push_back(S[i]);
dfs(S,i+1,path,result);
path.pop_back();
}
}
vector<vector<int> > subsetsWithDup(vector<int> &S) {
vector<vector<int>> result;
vector<int> path;
sort(S.begin(),S.end());
dfs(S,0,path,result);
return result;
}
};