Trees- 104. Maximum Depth of Binary Tree

#===================================
# Tanzila Islam
# Email: tanzilamohita@gmail.com
# Language: Python 3
#===================================

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def maxDepth(self, root: Optional[TreeNode]) -> int:
        if root is None:
            return 0
        else:
            leftDepth = self.maxDepth(root.left)
            rightDepth = self.maxDepth(root.right)
            
            if leftDepth > rightDepth:
                return leftDepth + 1
            else:
                return rightDepth + 1