第十二週

Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.

Each number in C may only be used once in the combination.

Note:
All numbers (including target) will be positive integers.
The solution set must not contain duplicate combinations.

依然是尋找組合解，同一數字只能被使用一次。遍歷數組的同時採用深度優先算法。

    vector<vector<int> > combinationSum2(vector<int> &num, int target) 
    {
        vector<vector<int>> res;
        sort(num.begin(),num.end());
        vector<int> temp;
        findCombination(res, 0, target, temp, num);
        return res;
    }
    void findCombination(vector<vector<int>>& res, const int start, const int target, vector<int>& temp, const vector<int>& num)
    {
        if(target==0)
        {
            res.push_back(temp);
            return;
        }
        else
        {
            for(int i = start;i<num.size();i++) 
            {
                if(num[i]>target) 
                    return;
                if(i&&num[i]==num[i-1]&&i>order) 
                    continue; 
                temp.push_back(num[i]),
                findCombination(res,i+1,target-num[i],temp,num);
                temp.pop_back();
            }
        }
    }