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Binary Tree Level Order Traversal
Binary Tree Level Order Traversal
Hard
Trees
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]]Level 0 is [3], level 1 is [9,20], and level 2 is [15,7].
Example 2
Input:
root = [1]Output:
[[1]]There is only one node at depth 0, so the traversal is [[1]].
Constraints
The number of nodes in the tree is in the range [0, 2000].-1000 <= Node.val <= 1000
solution.js
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Test Cases (2)
Test Case 1
Input:
[3,9,20,null,null,15,7]Expected Output:
[[3],[9,20],[15,7]]Test Case 2
Input:
[1]Expected Output:
[[1]]