Maximum Depth of Binary Tree
Examples
Example 1:
Input: root = [1, 2, 3, null, null, 4]
Output: 3
Example 2:
Input: root = []
Output: 0
Trees
Example 1:
Input: root = [1, 2, 3, null, null, 4]
Output: 3
Example 2:
Input: root = []
Output: 0
Given the root of a binary tree, return its depth.\n\nThe depth of a binary tree is defined as the number of nodes along the longest path from the root node down to the farthest leaf node.
0 <= The number of nodes in the tree <= 100-100 <= Node.val <= 100