590.N叉树的后序遍历

::: caution

原题链接：https://leetcode.cn/problems/n-ary-tree-postorder-traversal/

:::

思路

根据后序遍历定义求解

代码

/*
// 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:
    vector<int> res;
    void dfs(Node* node) {
        if (node) {
            for (int i = 0; i < node->children.size(); i++) {
                dfs(node->children[i]);
                res.push_back(node->children[i]->val);
            }
        }
    }

    vector<int> postorder(Node* root) {
        if (root) {
            dfs(root);
            res.push_back(root->val);
        }
        return res;
    }
};