Practice Complete Binary Tree Inserter

Read the task, work through the examples, and check your approach against the constraints. Use the original LeetCode task for coding and submissions.

Medium#919

LeetCode Problem

Complete Binary Tree Inserter

Tree Breadth-First Search Design Binary Tree

Problem Statement

CBTInserter(root) receives a nonempty complete binary tree: every level except possibly the last is full, and the last is filled left to right. insert(val) adds a node while preserving completeness and returns its parent value. get_root() returns the tree root. Practice approach: Breadth-first initialize a queue of nodes missing at least one child. Insert under the queue head, filling left before right; remove a parent once full and append the new node. Initialization is O(n), and later insertions are O(1). The example represents trees in level order.

Source: Complete Binary Tree Inserter on LeetCode. Use the original task for its coding environment and submissions.

Examples

# Example 1

Input

["CBTInserter","insert","insert","get_root"]
[[[4,7,9]],[2],[6],[]]

Output

[null,7,7,[4,7,9,2,6]]

Explanation

Both inserted nodes become children of 7, filling the next available positions from left to right.

Constraints

Initial tree contains 1 to 1000 nodes and is complete.

0 <= Node.val, val <= 5000

At most 10^4 total calls.

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