N叉树的前序遍历

Problem: 589. N 叉树的前序遍历

思路

前序遍历，遇到空节点返回

解题过程

对每个节点进行遍历

Code

/*
// 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 traversal(Node* cur, vector<int>& vec) {//cur当前遍历节点，vec储存值if (cur == NULL) return;vec.push_back(cur->val);//当前值储存（val节点所代表的值）(***把这一行移动到循环后面就变为后续遍历***）for (Node* child : cur->children) //遍历每个子节点traversal(child, vec);（***这个后面***）}vector<int> preorder(Node* root) {vector<int> result;         //储存结果traversal(root, result);return result;}
};