vector<vector<int> > subsets(vector<int> &S) {
vector<vector<int> > res;
vector<int> path;
sort(S.begin(), S.end());
subsetsHelper(res, path, S, 0);
return res;
}
void subsetsHelper(vector<vector<int> >& res, vector<int>& path, const vector<int>& S, int pos) {
res.push_back(path);
for(int i = pos; i < S.size(); ++i) {
path.push_back(S[i]);
subsetsHelper(res, path, S, i+1);
path.pop_back();
}
}
vector<vector<int> > subsetsHelper(vector<int> v, vector<int> temp,
vector<vector<int> > r, int s, int e, int index) {
r = updateResult(r, temp, index);
for(int i=s; i<=e; i++) {
temp[index] = v[i];
//printVector(temp);
r = subsetsHelper(v, temp, r, s+1, e, index+1);
s += 1;
}
return r;
}
void subsetsHelper(vector<int>& nums, int start, int size, vector<int> solution, vector<vector<int>>& result) {
if (size == 0) {
result.push_back(solution);
return;
}
for (int i = start; i < nums.size(); i++) {
solution.push_back(nums[i]);
subsetsHelper(nums, i+1, size-1, solution, result);
solution.pop_back();
}
}
void subsetsHelper(int start,vector<int>&nums){
if(start==nums.size())
return;
for(int i=start;i<nums.size();i++){
if(i>start&&nums[i]==nums[i-1])
continue;
tem.push_back(nums[i]);
res.push_back(tem);
subsetsHelper(i+1,nums);
tem.pop_back();
}
}
vector<vector<int>> subsets(vector<int>& nums) {
vector<vector<int>> result;
vector<int> solution;
// empty set
result.push_back(solution);
if (nums.size() <= 0) {
return result;
}
sort(nums.begin(), nums.end());
int n = nums.size();
for (int sub_size = 1; sub_size <= n; sub_size++) {
// using backtracking, get all subset, which size is sub_size
subsetsHelper(nums, 0, sub_size, solution, result);
}
return result;
}
vector<vector<int>> subsetsWithDup(vector<int>& nums) {
sort(nums.begin(),nums.end());
res.push_back(vector<int>());
subsetsHelper(0,nums);
return res;
}