Shulou(Shulou.com)06/01 Report--

In this issue, Xiaobian will bring you about how to print python binary tree from top to bottom. The article is rich in content and analyzed and described from a professional perspective. After reading this article, I hope you can gain something.

Title Description

Each node of the binary tree is printed from top to bottom, and nodes at the same level are printed in order from left to right.

Total nodes List[int]:

#Scenario 1: List +for loop

if not root:

return []

q = [root]

for node in q:

#Append only non-child nodes to queue

if node.left:

q.append(node.left)

if node.right:

q.append(node.right)

return [x.val for x in q]

Scenario 2 -Double-ended queues + while loop import collections

class Solution:

def levelOrder(self, root: TreeNode) -> List[int]:

#Scenario 2: Double-ended queue +while loop

if not root:

return []

q = collections.deque([root])

res = []

while q:

node = q.popleft()

res.append(node.val)

if node.left:

q.append(node.left)

if node.right:

q.append(node.right)

Return res The above is how to print python binary tree from top to bottom. If there is a similar doubt, please refer to the above analysis for understanding. If you want to know more about it, please pay attention to the industry information channel.

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