78. 子集
遍历全部,不用终止条件
class Solution {public:void backtracking(vector<int>& nums,int startIndex){result.push_back(path);for(int i=startIndex;i<nums.size();i++){path.push_back(nums[i]);backtracking(nums,i+1);path.pop_back();}}vector<vector<int>> subsets(vector<int>& nums) {backtracking(nums,0);return result;}vector<int> path;vector<vector<int>> result;};
