dsa · easy

Height of Binary Tree

GreyOrangeTreeRecursionFoundation

A binary tree node is [val, left, right] or None. Return the **number of nodes** on the longest root-to-leaf path (empty tree is 0).

Arguments

• root — the binary tree; each node is [val, left, right] or None

**Example:** [3, [9, None, None], [20, [15, None, None], [7, None, None]]] → 3.

Constraints

Number of nodes in [0, 10^4] Hidden tests include near-max size for this bound; a slower-than-intended solution TLEs.

Examples

Example 1

Input:
[3, [9, None, None], [20, [15, None, None], [7, None, None]]]

Expected:
3

Example 2

Input:
None

Expected:
0

Open in the Dojo editor