题解 | #加起来和为目标值的组合(二)#

#include <vector>
class Solution {
public:
    vector<vector<int> > result;
    vector<vector<int> > combinationSum2(vector<int> &num, int target) {
        if (num.empty()) return result;
        sort(num.begin(), num.end());
        vector<int> tmp;
        back_tracking(num, tmp, 0, 0, target);
        return result;
    }
    void back_tracking(vector<int>& num, vector<int>& tmp, int cur_sum, int begin, int target) {
        if (cur_sum >= target) {
            if (cur_sum == target) {
                result.push_back(tmp);
            }
            return;
        }
        for (int i = begin; i < num.size(); ++i) {
            if (i > begin && num[i] == num[i-1]) continue;
            tmp.push_back(num[i]);
            back_tracking(num, tmp, cur_sum + num[i], i + 1, target);
            tmp.pop_back();
        }
        return;
    }

};