层级顺序遍历二叉树 /* Binary tree - Level Order Traversal */
#include<iostream>
#include<queue>
using namespace std;struct Node {char data;Node *left;Node *right;
};// Function to print Nodes in a binary tree in Level order
void LevelOrder(Nod
前序遍历: /*** Definition for a binary tree node.* public class TreeNode {* int val;* TreeNode left;* TreeNode right;* TreeNode(int x) { val = x; }* }*/
class Solution {public List<Integer> preorderTraversal(TreeNode root) {List<Intege