Questions tagged [tree]
A tree is a graph in which there is exactly one path between any two nodes. It is often used as a hierarchical data structure.
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questions
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Set operations on a tree / Hierarchical set class
Initially, I posted this question on StackOverflow. I wanted to know if there's an existing library that implements the concept I have in mind, which is the following.
I want to define a hierarchy/...
4
votes
1answer
28 views
Counting unival subtrees - Follow Up
This code is a revised version of the implementation which asked for an advice on improvement. Original post here: Counting unival subtrees
Credits to: [Deduplicator], [Reinderien], [Toby Speight], [...
4
votes
1answer
67 views
Implementing an autocomplete system
Question:
Implement an autocomplete system. That is, given a query string s and a set of all possible query strings, return all strings in the set that have s as a prefix.
For example, given the query ...
2
votes
2answers
61 views
Lowest Common Ancestor in Binary Tree (Iterative)
In the below code I've implemented a method to find the lowest common ancestor of a binary tree.
This is an iterative approach using this pseudocode.
Please suggest any improvements that can be made.
<...
4
votes
1answer
65 views
A Concurrent Tree implementation with consistent snapshot capability
I have a tree in my application from which I need to periodically take a snapshot. I've been using locks so far, but after running into a few deadlock issues I decided to create a lock-free ...
4
votes
4answers
925 views
Check if a binary tree is symmetric in Python
I have solved the following Leetcode problem.
Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree [1,2,2,3,4,4,3] is symmetric....
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0answers
9 views
Tree design in db with same child twice and value store
I have a non-cyclic tree like the below sample representation. It has nodes and edges connecting them. The tree has the possibility of the same node connected multiple times to one parent. Like in the ...
9
votes
1answer
83 views
Construction and search of Kd-Tree in c++
I am not very fluent in C++ and want to construct a Kd-Tree in C++ based on this paper Efficient Locally Weighted Polynomial Regression Predictions, to use it to conduct some fast implementations of ...
2
votes
1answer
69 views
HackerRank - Binary tree to compute the Nth power of natural numbers that sum up to X
I'm trying to solve this challenge on HackerRank.
In short, given x and n, I have to determine how many ways I can pick numbers ...
8
votes
1answer
393 views
Using smart pointers to construct Binary Search Tree
I have three main questions:
Am I using std::unique_ptr correctly here? Using std::move and ...
5
votes
1answer
145 views
C++ : Red-Black Tree with std::unique_ptr
This is my C++ implementation of a Red-Black Tree, referring the CLRS book.
Half for fun, half for studying.
As implementing child node, I chose std::unique_ptr ...
1
vote
0answers
34 views
Find Invalid User Relationships in User to Manager Map (validate map as valid tree structure with no circular relationships)
We have a new service where an admin can upload a spreadsheet of new users they want to add to our application. During our processing we make a union map of all the users both existing and new ...
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0answers
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5
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1answer
292 views
Red-Black Tree Implementation in Python
i'm wondering if there are better practices, and optimizations, i could make on my code, to do things easier/faster. I have added comments, in many places in the code, to make understanding easier.
<...
3
votes
1answer
41 views
XML Tree Reformatter requested code. C#
So this is a post as per request in a different post on stack overflow: https://stackoverflow.com/questions/62412713/why-does-my-c-sharp-xml-code-only-work-when-i-enumerate-variable-enumerable. The ...
1
vote
1answer
113 views
Sum of all Paths in Binary Tree
Problem
For the given binary tree return the list which has sum of every paths in a tree. i.e Every path from root to leaf.
I've written following solution.
...
3
votes
0answers
53 views
Noughts and Crosses Terminal Game with AI
I created a game which can play tic-tac-toe with: 0 players (AI vs AI), 1 player (human vs AI) or 2 player (human vs human).
Here is the AI function which wraps around my innermost function. This ...
4
votes
1answer
55 views
AVL Tree implementation Based on VisualGo
I have tried implementing an AVL Tree on my own, based on visualising it. But i'm unsure how many testcases it work with, and how efficient it is. Are there any ways to make it efficient, and compact?
...
2
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0answers
47 views
Max Heap Implementation in Python
I decided to challenge myself to code this data structure by just seeing how it looks visually and this is what I got. I can change this easily to minheap by changing some greater than (>) operators. ...
1
vote
2answers
65 views
Leetcode: Cousins in Binary Tree
Mu solution to Leetcode problem Cousins in Binary Tree works, but the code feels bulky. Is there a better way to solve this problem, particularly to use less additional variables? I will appreciate ...
1
vote
1answer
50 views
Data mining in Java: finding undrawn lottery rows - follow-up
(See the previous (initial) iteration.)
This time, I have substantially reduced the usage of the final and this keywords. Also, ...
2
votes
2answers
86 views
Data mining in Java: finding undrawn lottery rows
(See the next iteration.)
Introduction
Suppose Evil Lottery Inc is interested in not paying millions of dollars back to players. They gather the drawn lottery rows first, after which they mine rows ...
1
vote
1answer
63 views
Depth First Search vs Breadth First Search
So after years of teaching myself, I think I'm ready to stand on the shoulders of giants and ask you a good question!
I have a tree of nodes. What I want is a function that returns an array of the ...
5
votes
2answers
124 views
Leftist Tree in Dyalog APL — can it be made more compact/idiomatic?
Following great feedback given in response to my previous question, I was encouraged to consider a different type of heap structure, the Leftist Tree. It lends itself better to a functional ...
2
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0answers
28 views
Traversing a tree with two types of nodes, while keeping track of all ancestors
I wrote code that stores an AWS Organization tree in a tree data structure in Rust. From the tree, I use a slightly modified preorder traversal algorithm to print all of the accounts in the ...
4
votes
2answers
151 views
Suffix Tree in Python
I was wondering why the following implementation of a Suffix Tree is 2000 times slower than using a similar data structure in C++ (I tested it using python3, pypy3 and pypy2). I know the bottleneck is ...
3
votes
1answer
69 views
LeetCode: Most Frequent Subtree Sum
My solution to LeetCode problem Most Frequent Subtree Sum works, but I have several questions regarding the code. I am also looking for an advice on how to improve the code.
Problem:
Given the ...
1
vote
1answer
33 views
5
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2answers
102 views
Binary Tree Preorder Traversal
What is the best way to move _add and _preorder methods in class Node to ...
4
votes
3answers
95 views
LeetCode: Validate Binary Search Tree C#
I was struggling with this question for many times,
and I have solved it every time, because I understand the concept.
but I can never get to a good concise solution which is easy to follow.
In a ...
1
vote
2answers
155 views
Binary tree pruning with BFS
Below the text of the exercise:
We are given the head node root of a binary tree, where additionally
every node's value is either a 0 or a 1.
Return the same tree where every subtree (of the ...
3
votes
1answer
663 views
Parsing Binary Tree Array in Python
I got this from a practice problem set, and looking for feedback on my approach.
Suppose you're given a binary tree represented as an array. Write a function that determines whether the left or ...
4
votes
0answers
158 views
JavaScript AVL Tree
I have been working through Introduction to Algorithms 3rd Edition, and have implemented an AVL tree through prototypal inheritance. The code presented here does work as expected based on the tests ...
2
votes
2answers
115 views
Iterative āpost orderā tree traversal [closed]
I wanted to get feedback on the correctness and efficiency of this post order traversal routine that my wife and I find really easy to grasp.
...
4
votes
1answer
64 views
Manipulate a tree layer wise
I built a tree in Haskell where every node has a number that is unique in its path from root to leaf. Nodes have a dedicated list for children that are leaves. ...
4
votes
3answers
632 views
2
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1answer
237 views
Python Fenwick Tree
I am trying to solve this question: https://open.kattis.com/problems/fenwick
A Fenwick Tree (also known as a Binary Indexed Tree) is a data
structure on an array which enables fast (š(logš)) ...
3
votes
1answer
206 views
F# Binary Tree and Tree Traversal
So for an side exercise on exercism I implemented a BinarySearchTree.
I was confident in implementing the creation of the binary tree. But I'm very unsure about the traversal of the tree. So I came ...
5
votes
1answer
755 views
Calculating the average of all nodes in a Binary Search Tree using visitors
I'm required to calculate the average value of all nodes in a BST using a Visitor, I'm not sure if I did this correctly or if i could just calculate the average ...
3
votes
1answer
71 views
Simple tree addition implementation
I am trying to learn Rust and I feel like a dummy every step of the way.
I went through the tutorial on making lists in Rust. I am trying to apply the knowledge ...
1
vote
1answer
50 views
Don't include root directory in HTML tree
I've written a function to create an HTML tree from JSON.
...
3
votes
2answers
100 views
Performance Improvement for Subtree for another tree
I was doing this algo on leetcode: https://leetcode.com/problems/subtree-of-another-tree/
Question:
Given two non-empty binary trees s and t, check whether tree t has exactly the same structure and ...
12
votes
4answers
2k views
Extraction of value from a dict-tree, given a path of arbitrary length
Problem: We read a complex json-file which grants us a tree in terms of a python "dict of dicts". We're then requested to retrieve a specific path from the tree, represented by a list of elements. The ...
1
vote
0answers
39 views
BST range search
I'd like some input on my implementation of bst-range, which follows below.
Before we can get to bst-range, we first need some setup code to build the BST.
(You ...
10
votes
2answers
875 views
Iterator for traversing a tree [v2]
this is an update of the implementation after I followed the feedback from Iterator for traversing a tree. After that I did changed quite a bit on the design and decided to ask for another round of ...
3
votes
1answer
87 views
6
votes
1answer
55 views
BST with node count
I took a simple BST implementation which is only really a set (i.e. just element, not key value), and decided to add a node count. I was translating this, which is explained here.
In particular the ...
3
votes
2answers
221 views
LeetCode: Diameter of Binary Tree
https://leetcode.com/problems/diameter-of-binary-tree/
Given a binary tree, you need to compute the length of the diameter of
the tree. The diameter of a binary tree is the length of the longest
...
1
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0answers
67 views
leetcode 230: kth smallest element in a Binary Search Tree
Here is my implementation: the goal of the algorithm is to find the kth smallest element in a BST.
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2
votes
2answers
578 views
Ternary search tree implementation in python 3
I have implemented a Ternary search tree. It works well. But if you think something needs to be improved, say it. This code was tested in Python 3.7.4.
...
