[BFS] Binary Tree Level Order Traversal

[sudosf]

Problem

Return the level-order traversal of a binary tree's values as a list of lists.

References

• LeetCode: https://leetcode.com/problems/binary-tree-level-order-traversal/
• GFG: https://www.geeksforgeeks.org/problems/level-order-traversal/1
• Sheet: https://www.risingbrain.org/sheet#tree (BFS/Level-Order Pattern: Two Pointers (Arrays) #3)
• Parent: Pattern: BFS (Trees + Graphs) #26

Difficulty

🟡 Medium

Companies

Amazon, Google, Goldman Sachs

Notes

Language: Java
Track level size at each iteration using queue.size() before the inner loop.