leetcode 590.N-ary Tree Postorder Traversal N叉树的后序遍历

递归方法

C++代码：

 /*
 // Definition for a Node.
 class Node {
 public:
     int val;
     vector<Node*> children;

     Node() {}

     Node(int _val, vector<Node*> _children) {
         val = _val;
         children = _children;
     }
 };
 */
 class Solution {
 public:
     vector<int> postorder(Node* root) {
         vector<int>res;
         post(root,res);
         return res;
     }
     void post(Node*root, vector<int> &res){
         if(root==NULL) return;
         for(int i=;i<root->children.size();i++){
             post(root->children[i],res);
         }
         res.push_back(root->val);
     }
 };