题解 | #二叉树的最大深度#

# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param root TreeNode类 
# @return int整型
#
class Solution:
    def maxDepth(self , root: TreeNode) -> int:
        # 层次遍历
        count = 0
        if root is None:
            return count

        tree_list = []
        tree_list.append(root)

        while len(tree_list) > 0:
            count += 1
            for i in range(len(tree_list)):
                node = tree_list.pop(0)
                if node.left:
                    tree_list.append(node.left)
                if node.right:
                    tree_list.append(node.right)

        return count