To prove safety offer_ binary tree _ zigzag print order binary tree

Binary Tree zigzag print order

Title Description
Please implement a function according to a binary tree zigzag print, i.e., the first row from left to right order of printing, the print order of the second layer is from right to left, the third row from left to right order of printing, other line and so on.

Answers

# -*- coding:utf-8 -*-
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
class Solution:
    def Print(self, pRoot):
        # write code here
        resultarray = []
        if not pRoot:
            return resultarray
        currnodes = [pRoot]
        flag = True
        while currnodes:
            currvalues = []
            nextnodes = []
            for node in currnodes:
                currvalues.append(node.val)
                if node.left:
                    nextnodes.append(node.left)
                if node.right:
                    nextnodes.append(node.right)
            currnodes = nextnodes
            resultarray.append(currvalues) if flag else resultarray.append(currvalues[::-1])
            flag = not flag
        return resultarray