Solution (leetcode-in-java 1.20 API)

java.lang.Object
- g0101_0200.s0102_binary_tree_level_order_traversal.Solution

```
public class Solution
extends Object
```
102 - Binary Tree Level Order Traversal.
Medium

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:

Input: root = [3,9,20,null,null,15,7]

Output: [[3],[9,20],[15,7]]

Example 2:

Input: root = [1]

Output: 1

Example 3:

Input: root = []

Output: []

Constraints:
- The number of nodes in the tree is in the range [0, 2000].
- -1000 <= Node.val <= 1000

- Constructor Summary
  
  Constructors
  Constructor Description
  
  Solution()
- Method Summary
  
  All Methods Instance Methods Concrete Methods
  Modifier and Type Method Description
  
  List<List<Integer>> levelOrder(TreeNode root)
  - Methods inherited from class java.lang.Object
    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail
- Solution
```
public Solution()
```

Method Detail

levelOrder

public List<List<Integer>> levelOrder(TreeNode root)