Leecode 590. N 叉树的后序遍历

原题链接：Leecode 590. N 叉树的后序遍历


递归

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

    Node() {}

    Node(int _val) {
        val = _val;
    }

    Node(int _val, vector<Node*> _children) {
        val = _val;
        children = _children;
    }
};
*/

class Solution {
public:
    void post(Node* root,vector<int>& r)
    {
        for(int i=0;i<root->children.size();i++)
        {
            post(root->children[i],r);
        }
        r.push_back(root->val);
    }
    vector<int> postorder(Node* root) {
        if(!root) return {};
        vector<int> r;
        post(root,r);
        return r;
    }
};