Leetcode_Medium_problem-solutions/39. Combination Sum.cpp at main · reebaseb/Leetcode_Medium_problem-solutions · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
// C++

class Solution
{
    void combination(vector<int>& candidates, int target, vector<int> currComb, int currSum, int currIndex, vector<vector<int>>& ans)
    {
        if(currSum>target) return; //backtrack
        if(currSum==target)
        {
            ans.push_back(currComb);
            return;
        }

        for(int i=currIndex; i<candidates.size(); i++)
        {
            currComb.push_back(candidates[i]);
            currSum+=candidates[i];
            combination(candidates, target, currComb, currSum, i, ans);
            currComb.pop_back();
            currSum-=candidates[i];
        }

    }
public:
    vector<vector<int>> combinationSum(vector<int>& candidates, int target)
    {
        vector<vector<int>> ans;
        vector<int> currComb;
        combination(candidates, target, currComb, 0, 0, ans);
        return ans;
    }
};