从上到下打印二叉树.py

# -*- coding:utf-8 -*-
class TreeNode:
    def __init__(self, x):
        self.val = x
        self.left = None
        self.right = None


class Solution:
    # 返回从上到下每个节点值列表，例：[1,2,3]
    def PrintFromTopToBottom(self, root):
        # write code here
        if root is None:
            return []
        result = []
        queue = [root]
        while queue:
            currentroot = queue.pop(0)
            result.append(currentroot.val)
            if currentroot.left:
                queue.append(currentroot.left)
            if currentroot.right:
                queue.append(currentroot.right)
        return result


pNode1 = TreeNode(8)
pNode2 = TreeNode(6)
pNode3 = TreeNode(10)
pNode4 = TreeNode(5)
pNode5 = TreeNode(7)
pNode6 = TreeNode(9)
pNode7 = TreeNode(11)
pNode1.left = pNode2
pNode1.right = pNode3
pNode2.left = pNode4
pNode2.right = pNode5
pNode3.left = pNode6
pNode3.right = pNode7
s = Solution()
print(s.PrintFromTopToBottom(pNode1))