題目描述：

https://leetcode-cn.com/problems/n-ary-tree-level-order-traversal/

代碼：

class Solution {
private:
   vector<vector<int> > ans;
   vector<int> anss;
   queue<Node *> myqueue;
public:
   vector<vector<int>> levelOrder(Node* root) {
       if(!root)
           return ans;
       myqueue.push(root);
       while(!myqueue.empty())
       {
           anss.erase(anss.begin(), anss.end());
           int size = myqueue.size();
           for(int i=0; i<size; i++)
           {
               Node * temp = myqueue.front();
               myqueue.pop();
               anss.push_back(temp->val);
               if(!temp->children.empty())
               {
                   for(Node* child : temp->children)
                       myqueue.push(child);
               }
           }
           ans.push_back(anss);
       }
       return ans;   
   }    
};