python3题解 | #按之字形顺序打印二叉树#

from queue import Queue
# 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 pRoot TreeNode类 
# @return int整型二维数组
#
class Solution:
    def Print(self , pRoot: TreeNode) -> List[List[int]]:
        # write code here
        if pRoot is None: return []
        if pRoot:
            res = []
            queue = [pRoot]
            i=-1
            hhh = True
            while queue:
                ceng = []
                for _ in range(len(queue)):
                    node = queue.pop(0)
                    ceng.append(node.val)
                    if node.left:
                        queue.append(node.left)
                    if node.right:
                        queue.append(node.right)
                hhh = not hhh
                if hhh:
                    res.append(ceng[::-1])
                if not hhh:
                    res.append(ceng)
            return res