代码随想录day24 | 77. 组合

class Solution {
public:
    vector<vector<int>> combine(int n, int k) {
        backTracking(n, k, 1);
        return result;
    }
private: 
    vector<int> path;
    vector<vector<int>> result;
    void backTracking(const int& n, const int& k, int startIndex) {
        if(path.size() == k){
            result.push_back(path);
            return;
        }
        for(int i = startIndex; i <= n - (k-path.size()) + 1; i++) {
            path.push_back(i);
            backTracking(n, k, i+1);
            path.pop_back();
        }
    }
};