Maximum Depth of Binary Tree
EasyP1Coding
Given the root of a binary tree, return its maximum depth: the number of nodes on the longest path from the root down to a leaf. An empty tree has depth 0.
Tree nodes have val, left and right. The class TreeNode is already defined for you. The tree arrives in level-order form (as in the examples) and you receive its root, which is null for an empty tree.
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
Constraints
- The number of nodes is in the range [0, 10^4].
- -100 <= Node.val <= 100
Hints
Give it a real attempt first. Run shows which examples fail.
Saved automatically
Run checks the 3 visible tests, Submit all 9. ⌘Enter runs, ⌘⇧Enter submits.