LeetCode – Refresh – Combinations

Same algorithm with combination. Input as the (1..n), constraint is that the length of each combine should be k.

class Solution {
public:
    void getComb(vector<vector<int> > &result, vector<int> current, int n, int k, int start) {
        if (current.size() == k) {
            result.push_back(current);
            return;
        }
        for (int i = start; i <= n; i++) {
            current.push_back(i);
            getComb(result, current, n, k, i+1);
            current.pop_back();
        }
    }
    vector<vector<int> > combine(int n, int k) {
        vector<vector<int> > result;
        getComb(result, vector<int> (), n, k, 1);
        return result;
    }
};