最少元素和为 K 的子集：DFS 算法实现

void dfs(vector path, int sum, int start) //求解算法 { if (sum == k) //找到一组解 { if (path.size() < minNum) //更新最优解 { ans = path; minNum = path.size(); } return; } if (start >= n || sum > k) //递归边界 return; path.push_back(a[start]); //选择当前数 dfs(path, sum + a[start], start + 1); path.pop_back(); //回溯 dfs(path, sum, start + 1); //不选当前数，继续向后搜索 }