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Problem Challenge 1: Connect All Level Order Siblings (medium)

Problem Statement

Given a root of the binary tree, connect each node with its level order successor. The last node of each level should point to the first node of the next level.

Examples

Example 1

  • Input: root = [1, 2, 3, 4, 5, 6, 7]
Image
  • Output: 1 -> 2 -> 3 -> 4 -> 5 -> 6 -> 7 -> null
  • Explanation: The tree is traversed level by level using BFS. Each node is connected to its next node in level order traversal, including connections between levels. The last node (7) points to null.

Example 2

  • Input: root = [12, 7, 1, 9, null, 10, 5]
Image
  • Output: 12 -> 7 -> 1 -> 9 -> 10 -> 5 -> null
  • Explanation: Each node is connected to its next node in level order traversal. The last node (5) points to null, completing the connection of all level order siblings.

Constraints:

  • The number of nodes in the tree is in the range [0, 2<sup>12</sup> - 1].
  • -1000 <= Node.val <= 1000

Try it yourself

Try solving this question here:

Python3
Python3
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