time and space complexity creating vector of elements at each levels of a binary tree(NON-BST)

Could you please help me understand calculating the time and space complexity of the below function.

function(): Role: create vector of nodes at each levels

1. create a queue.


2. add the root


3. copy the elements in the queue to the vector.


4. traverse the vector and append the child(left & right) to the queue.


5. repeat steps 3 & 4 until the queue is empty.

below is the code.

struct node {
     int value;
     struct node* p_left;
     struct node* p_right;
};

void levels_list(struct node* p_btree) {
     if(!p_btree) {
          return ;
     }


     std::queue<struct node*> q;
     std::vector<std::vector<struct node*> > v1;

     q.push(p_btree);
     bool choice = false;

     while(!q.empty()) {
          std::vector<struct node*> v;

          while(!q.empty()) {
               v.push_back(q.front());
               q.pop();
          }

          for(int i = 0; i < v.size(); i++) {
               if(v[i]->p_left) {
                    q.push(v[i]->p_left);
               }
               if(v[i]->p_right) {
                    q.push(v[i]->p_right);
               }
          }

          v1.push_back(v);
          v.clear();
     }
}

I see that it is O(n^2), am I correct? There are two loops the first one is outer and the second one is the inner which pushes the elements into the vector from the queue.

Thanks