class Solution
{
public:
vector<vector<int> > combinationSum(vector<int> &candidates, int target)
{
vector<int> vecTmp;
m_vecRet.clear();
sort(candidates.begin(), candidates.end());
combination(candidates, 0, vecTmp, target);
return m_vecRet;
}
private:
void combination(const vector<int> &candidates, size_t idx, vector<int> &curr, int target)
{
if (target == 0)
{
m_vecRet.push_back(curr);
}
else
{
// i starts from idx to make sure results are distinct.
for (size_t i = idx; i < candidates.size(); ++i)
{
if (target >= candidates[i])
{
curr.push_back(candidates[i]);
combination(candidates, i, curr, target - candidates[i]);
curr.pop_back();
}
}
}
}
private:
vector<vector<int> > m_vecRet;
};