質問する

に答える

# 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:
        global maxDepth
        if root:
            maxDepth = 1
            solution(root, 1)
            return maxDepth
        else:
            return 0
        
        
        
def solution(thisNode, depth):
    global maxDepth
    if thisNode.left is None and thisNode.right is None:
        maxDepth = max(maxDepth, depth)
        return
    if thisNode.left:
        solution(thisNode.left, depth+1)
    if thisNode.right:
        solution(thisNode.right, depth+1)

結果