78. 子集——回溯

class Solution {
public:
    vector> vec_vec_int;
    vector vec_int;
    vector> subsets(vector& nums) {
        int n = nums.size();
        backtrack(nums, 0);
        return vec_vec_int;
    }
    void backtrack(vector& nums, int left){
        vec_vec_int.push_back(vec_int);
        for(int i = left; i < nums.size(); i++){
            vec_int.push_back(nums[i]);
            backtrack(nums, i + 1);
            vec_int.pop_back();
        }
    }
};

Accepted
10/10 cases passed (0 ms)
Your runtime beats 100 % of cpp submissions
Your memory usage beats 76.08 % of cpp submissions (6.9 MB)