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Tree BFS & DFS/medium

Binary Tree Level Order Traversal

tree-bfs-dfsbinary-tree-level-order-traversal

Binary Tree Level Order Traversal

Given the root of a binary tree (represented in level order), return the level order traversal of its nodes' values (i.e., from left to right, level by level).

Example 1

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

Constraints

  • Number of nodes is in range [0, 2000].

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Input:
{
  "tree": [
    3,
    9,
    20,
    null,
    null,
    15,
    7
  ]
}
Expected Output:
[
  [
    3
  ],
  [
    9,
    20
  ],
  [
    15,
    7
  ]
]