Binary Tree Level Order Traversal
Detailed guide and Python implementation for the 'Binary Tree Level Order Traversal' problem.
Problem Statement
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).
The tree is represented as a level-order list. Implement a function levelOrder(root: list) -> list that returns a list of lists, where each inner list contains the values at that level.
- •The number of nodes in the tree is in the range [0, 2000]
- •-1000 <= Node.val <= 1000
Examples
[3,9,20,None,None,15,7]
[[3],[9,20],[15,7]]
Level 0: [3]. Level 1: [9,20]. Level 2: [15,7].
[1]
[[1]]
Only one node at level 0.
[]
[]
Empty tree has no levels.
Need a Hint?
Edge Cases to Watch
- Empty input structures
- Single element inputs
- Large numerical bounds
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