The test cases used in the code below are drawn as a tree and look like this:
When creating the tree, the array is given, and’#’ represents an illegal value , That is, the node is empty.
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Tag: binary tree
[Data Structure] Tree and Binary Tree
Tree
Tree is a typical nonlinear data structure, It can be well applied to data collections that describe branching and hierarchical characteristics. It is a limited collection T composed of
[Data Structure] Closing of the binary tree
The node structure of the binary tree is now redefined as follows: leftchild lefttag _date righttag rightchild where: when lefttag=0, leftchild points to the left child;
[Data Structure] Finding of Binary Trees and Calculation of Knights
The previous blog has basically introduced the basic algorithm of the binary tree. This article mainly introduces the search of nodes in the binary tree and the number of subtrees in the Kth row.
[Data Structure] – surrounding the two-fork tree
[Background]
The third stage of learning “Introduction to Data Structure” is almost the same It’s about to end. When doing the question, I will suddenly find out, oh, it turned out to be so.
[Data Structure] Basic Knowledge of Binary Tree
Total number of branches = number of summary points-1
Number of leaf nodes = number of double branch nodes + 1
Preface Traversal: Root left and right
Mid-order traversal: left roo
101. Symmetrical binary tree
Given a binary tree, check whether it is mirror-symmetrical.
For example, the binary tree [1,2,2,3,4,4,3] is symmetrical.
1
/ \
2 2
/ \ / \
3 4 4 3
But the following (1,2,2,null,3,nu
2019.9.26 – Implementation code of the binary tree
# coding:utf-8
class Node(object):
“”””””
def __init__(self, item):
self. elem = item
self,lchild = None
self.rchild = None
class Tree(object):
“””Binary Tree”””
def __init__(sel
144. Pre-sequence traversal of the binary tree
Given a binary tree, return its previous traversal.
Example:
Input: [1,null,2,3]
1
\
2
/
3 Output: [1,2,3]
Advanced: The recursive algorithm is very simple, can you do it through