LeetCode 102. Binary Tree Level Order Traversal
Question
Given the root
of a binary tree, return the level order traversal of its nodes’ values. (i.e., from left to right, level by level).
Example 1:
![tree1](https://i.imgur.com/SoJofIS.jpg)
1 | Input: root = [3,9,20,null,null,15,7] |
Example 2:
1 | Input: root = [1] |
Example 3:
1 | Input: root = [] |
Constraints:
- The number of nodes in the tree is in the range
[0, 2000]
. -1000 <= Node.val <= 1000
Source: https://leetcode.com/problems/binary-tree-level-order-traversal/
Solution
Use queue size in BFS to implement layer-ordre traversal of a tree.
1 | class TreeNode { |
LeetCode 102. Binary Tree Level Order Traversal
http://yenotes.org/2022/01/25/LeetCode-102-Binary-Tree-Level-Order-Traversal/