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

In this issue, the editor will bring you about the sequence traversal of the binary tree in big data. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.

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Topic description

According to sequence traversal, the node value of a binary tree is returned from bottom to top (accessed from left to right layer by layer from bottom to top). For example, enter the following tree:

Return to [[15pr 7], [9je 20], [3]].

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Answer to the question

The sequence traversal of the binary tree is basically the same, but the output order has changed a bit, so although the BFS and DFS algorithms are used, as long as the last question can change the output order, the difficulty will change from intermediate to simple. Idea: breadth-first algorithm (BFS) # Definition for a binary tree node.# class TreeNode:# def _ init__ (self, x): # self.val = x # self.left = None# self.right = Noneclass Solution: def levelOrderBottom (self) Root: TreeNode)-> list [list]: if not root: return [] result = [] level = [root] while len (level) > 0: tmp1= [] res = [] for node in level: if node.left: tmp1.append (node.left) ) if node.right: tmp1.append (node.right) res.append (node.val) level = tmp1 result.append (res) # output this will be fine return result [::-1]

The above is what the sequence traversal of the binary tree in big data is shared by the editor. If you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

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