40.组合总和 II

原题链接：40.组合总和 II

思路：

太抽象了 建议看题解
代码随想录该题题解

全代码：

class Solution {
public:
    vector<vector<int>>result;
    vector<int> path;
    bool picking = false;
    void backtracking(vector<int>& candidates, int target,int sum, int startIndex,vector<bool>& used){
        if(sum == target){
            result.push_back(path); return;
        } 

        for(int i = startIndex; i < candidates.size() && sum + candidates[i] <= target; i++)
        {
            if(i > 0 && candidates[i] == candidates[i - 1] && used[i - 1] == false) 
            {
                continue;
            }
            sum += candidates[i];
            path.push_back(candidates[i]);
            used[i] = true;
            backtracking(candidates,target,sum,i + 1,used);
            used[i] = false;
            sum -= candidates[i];
            path.pop_back();

        }
    }
    vector<vector<int>> combinationSum2(vector<int>& candidates, int target) {
         vector<bool> used(candidates.size(), false);
         sort(candidates.begin(), candidates.end());
        backtracking(candidates,target,0,0,used);
        return result;
    }
};