题目描述

算法1

() $O()$

C++ 代码

class Solution {
public:
    vector<vector<int> > combinationSum2(vector<int> &candidates, int target) {
        sort(candidates.begin(), candidates.end());
        vector<vector<int> > res;
        vector<int> combination;
        dfs(candidates, target, res, combination, 0);
        return res;
    }
private:
    void dfs(vector<int> &candidates, int target, vector<vector<int> > &res, vector<int> &combination, int begin) {
        if (!target) {
            res.push_back(combination);
            return;
        }
        for (int i = begin; i != candidates.size() && target >= candidates[i]; ++i)
            if (i == begin || candidates[i] != candidates[i - 1]) {
                combination.push_back(candidates[i]);
                dfs(candidates, target - candidates[i], res, combination, i + 1);
                combination.pop_back();
            }
    }
};