Level Grouping of Nodes (Medium)

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Level Grouping of Nodes

Medium

Trees

In "Level Grouping of Nodes", the binary tree is provided in array form (level-order with null gaps).

Return node values grouped by depth from top to bottom and left to right.

Example 1

Input:root = [14,15,16,null,17,18,null]

Output:[[14],[15,16],[17,18]]

For input root = [14,15,16,null,17,18,null], nodes are grouped by depth from top to bottom, yielding [[14],[15,16],[17,18]]. Therefore, return [[14],[15,16],[17,18]].

Example 2

Input:root = [24,25,26,27,null,null,28]

Output:[[24],[25,26],[27,28]]

For input root = [24,25,26,27,null,null,28], nodes are grouped by depth from top to bottom, yielding [[24],[25,26],[27,28]]. Therefore, return [[24],[25,26],[27,28]].

Constraints

0 <= number of nodes <= 2000
-1000 <= Node.val <= 1000

solution.js

Test Cases (2)

Test Case 1

Input:

[14,15,16,null,17,18,null]

Expected Output:

[[14],[15,16],[17,18]]

Test Case 2

Input:

[24,25,26,27,null,null,28]

Expected Output:

[[24],[25,26],[27,28]]