40.Combination Sum II

class Solution {
public:
    vector<vector<int> > combinationSum2(vector<int> &num, int target) {
        vector<vector<int> > result;
        vector<vector<int> > subsets;
        vector<int> empty;
        subsets.push_back(empty);
        
        sort(num.begin(), num.end());
        for(int i = 0; i < num.size();)
        {//for each number
            int count = 0;
            int cur = num[i];
            if(cur > target)    //end
                return result;
            while(i < num.size() && num[i] == cur)
            {//repeat count
                i ++;
                count ++;
            }
            int size = subsets.size();    //orinigal size instead of calling size() function
            for(int j = 0; j < size; j ++)
            {
                vector<int> sub = subsets[j];
                int tempCount = count;
                while(tempCount --)
                {
                    sub.push_back(cur);
                    int sum = accumulate(sub.begin(), sub.end(), 0);
                    if(sum == target)
                    {
                        result.push_back(sub);
                        subsets.push_back(sub);
                    }
                    else if(sum < target)
                        subsets.push_back(sub);
                }
            }
        }
        return result;
    }
};