题解 | #集合的所有子集(一)#

回溯法

class Solution {
public:
  
    vector<vector<int>> ret;
    vector<vector<int>> subsets(vector<int>& nums) {
        vector<int> path;
        backTracking(nums, path, 0);
        return ret;
    }
    void backTracking(vector<int>& nums, vector<int>& path, int idx)
    {
        ret.push_back(path);
        if(idx == nums.size())
        {
            return;
        }
        for(int i = idx;i < nums.size();i++)
        {
            path.push_back(nums[i]);
            backTracking(nums, path, i+1);
            path.pop_back();
        }
    }
};