Given the root
of a binary tree, return its maximum depth.
A binary tree's maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.
Example 1:
Input: root = [3,9,20,null,null,15,7] Output: 3
Example 2:
Input: root = [1,null,2] Output: 2
Example 3:
Input: root = [] Output: 0
Example 4:
Input: root = [0] Output: 1
Constraints:
- The number of nodes in the tree is in the range
[0, 104]
. -100 <= Node.val <= 100
[Tree] [Depth-First Search] [Breadth-First Search] [Binary Tree]
- Balanced Binary Tree (Easy)
- Minimum Depth of Binary Tree (Easy)
- Maximum Depth of N-ary Tree (Easy)
- Time Needed to Inform All Employees (Medium)