Maximum Depth of Binary Tree LeetCode Solution | Easy Approach

Maximum Depth of Binary Tree 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

Constraints:

• The number of nodes in the tree is in the range [0, 104].
• -100 <= Node.val <= 100

Maximum Depth of Binary Tree Solutions

✅Time: O(n)
✅Space: O(1)

C++

class Solution {
 public:
  int maxDepth(TreeNode* root) {
    if (!root)
      return 0;
    return 1 + max(maxDepth(root->left), maxDepth(root->right));
  }
};

Java

 class Solution {
  public int maxDepth(TreeNode root) {
    if (root == null)
      return 0;
    return 1 + Math.max(maxDepth(root.left), maxDepth(root.right));
  }
}

Python

class Solution:
  def maxDepth(self, root: Optional[TreeNode]) -> int:
    if not root:
      return 0
    return 1 + max(self.maxDepth(root.left), self.maxDepth(root.right))

Watch Tutorial

Checkout more Solutions here