[Leetcode] 104. Maximum Depth of Binary Tree

문제 바로가기
leaf node에서 backtracking으로 root까지의 길이 중 최대 값을 계산한다.

Time Complexity: $O(n)$
Space Complexity: $O(\log n)$ - worse case: $O(n)$

# 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: TreeNode) -> int:
        if root is None:
            return 0
        
        return max(self.maxDepth(root.left), self.maxDepth(root.right)) + 1