Stack Overflow
Stack Overflow

Questions tagged [union-find]

A union/find data structure is a data structure used for maintaining a partition of a set.

184 questions
0
votes
0 answers

Self-referential struct in c++ for union-find

The following is a Java implementation of union-find, and I wish to replicate the same in C++: class v_rank{ int position, rank; v_rank parent; public v_rank(int position){ this.position = position; rank = 0; …
Karmah24
  • 485
  • 1
  • 5
  • 14
0
votes
1 answer

Union Find in Java

I am trying to implement the union-find algorithm. Basically the part of the algorithm that I am struggling with is the union part. What is supposed to happen is that there is a list of numbers (starts off with all of them being their index in the…
Ben Naylor
  • 29
  • 6
0
votes
1 answer

Union-find algorithm does not return expected result

I implemented the following union-find algorithm using this example: import numpy as np class UnionFind(object): def __init__(self, edges): self.edges = edges self.n_edges = np.max(edges) + 1 self.data =…
Gilfoyle
  • 3,282
  • 3
  • 47
  • 83
0
votes
1 answer

finding if there is a way from the top to a specific element in 2-dimensional array

I have a 2-dimensional array, I want to check if there is any way from the top row to a specific element in the array. The way means: that there is continuously connected 1 from top to the element. I've implemented a function to solve it: I can…
Ahmad Ali
  • 704
  • 1
  • 10
  • 28
0
votes
1 answer

proof of time complexity of union find with path compression

The Wikipedia page: wikipedia page states that If m operations, either Union or Find, are applied to n elements, the total run time is O(m log*n). The detailed analysis arrived at this result is : My questions are: Shouldn't the sum be…
alternative_chipmunk
  • 1
  • 2
0
votes
1 answer

Find the number of connected components in undirected graph using Union Find

I've been staring at this algorithm for a while but couldn't spot what I've missed. Logic: Init all isolated components union frm, to component in each edge and decrement # components if those components aren't already connected. Question: how…
jen007
  • 1,389
  • 3
  • 15
  • 19
0
votes
0 answers

Use union-find data structure to find connected component in a graph through Python

I'm working on building a graph for word ladder problem using Python. I try to use union-find data structure to find connected component in the graph, but since I'm new to programming, I feel very confused how to implement it in Python even I have…
FantasticAI
  • 99
  • 4
0
votes
2 answers

How do I use union find data structure to group Strings?

I have been using Union-Find (Disjoint set) for a lot of graph problems and know how this works. But I have almost always used this data structure with integers or numbers. While solving this leetcode problem I need to group strings and I am…
Ezio
  • 2,837
  • 2
  • 29
  • 45
0
votes
1 answer

Disjoint-Set (union-find) data structure in MATLAB

Are there any implementations of the union-find algorithm in MATLAB? If not, is it possible to implement it using a classdef or any other method? I looked online a lot and couldn't find any implementations for MATLAB! This was the last place I could…
saad.sawash
  • 229
  • 1
  • 10
0
votes
1 answer

How to select elements in a Quick union operation?

There are a set of elements S = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}. Here there are 10 elements (N = 10). An array arr to manage the connectivity of the elements. Arr[ ] that is indexed by elements of sets, which are of size N (as N elements in set),…
Kshitij Zutshi
  • 69
  • 7
0
votes
1 answer

Implementing Union-Find, getting TypeError: 'builtin_function_or_method' object is not subscriptable

I am trying to implement a quick-union with path compression algorithm and for some reason I'm getting a TypeError: 'builtin_function_or_method' object is not subscriptable when testing. It all looks good to me. Here's the code; I appreciate your…
qotsa42
  • 147
  • 1
  • 1
  • 11
0
votes
2 answers

Why is the time complexity O(lgN) for an operation in weighted union find algorithm?

So everywhere I see weighted union find algorithm, they use this approach: Maintain an array pointing to the parent node of a particular node Maintain an array denoting the size of the tree a node is in For union (p,q) merge the smaller tree with…
Little_idiot
  • 125
  • 1
  • 8
0
votes
1 answer

How can I implement the Union-Find algorithm?

I'm trying to implement the Union-Find algorithm, but all of the implementations i've looked up use integers. I need to implement the algorithm so that I can call the union() and the connected() methods in this way: union(Vertex v, Vertex, w) -…
Nicolás Cárdenas
  • 53
  • 5
0
votes
1 answer

How to implement the operation FindMin(x) on a union-find data structure?

S represents the set of integers from 1 to n. Consider the union-find data structure where - besides the operations union(A, B) and find(x) - you are interested in returning the minimum element of the set to which x belongs. Suggest a data structure…
pippi2424
  • 21
  • 5
0
votes
1 answer

How to correctly implement wighted union and path compression in a UnionFind data structure

I am trying to implement a Union-Find/Disjoint-Set data structure in C, using weighted Union and path compression in Find. I have some questions as to how the weighted union should be implemented to reduce time complexity when compared to the non…
Desperados
  • 434
  • 5
  • 13
1 2 3
…
12 13