A basic union-find data structure for node.js
MIT License
A basic union-find data structure for node.js. For more information, see wikipdia:
Union find data structures solve the incremental connectivity problem. (That is maintaining a spanning forest under incremental insertions of edges.) To handle fully dynamic connectivity, you can use a dynamic forest data structure.
Here is an example showing how to do connected component labelling. Assume we are given a graph with VERTEX_COUNT
vertices and a list of edges stored in array represented by pairs of vertex indices:
//Import data structure
var UnionFind = require('union-find')
var VERTEX_COUNT = 8
var edges = [
[0,1],
[1,2],
[2,3],
[5,6],
[7,1]
]
//Link all the nodes together
var forest = new UnionFind(VERTEX_COUNT)
for(var i=0; i<edges.length; ++i) {
forest.link(edges[i][0], edges[i][1])
}
//Label components
var labels = new Array(VERTEX_COUNT)
for(var i=0; i<VERTEX_COUNT; ++i) {
labels[i] = forest.find(i)
}
npm install union-find
var UnionFind = require('union-find')
var forest = new UnionFind(numVertices)
Creates a new union-find data structure.
numVertices
is the number of vertices in the graphReturns A new union-find data structure
forest.length
Returns the number of vertices in the forest
forest.makeSet()
Creates a new vertex
Returns An integer id for the new vertex
forest.find(v)
Returns an identifier representing the connected component of any given vertex
Returns An integer id representing the connected component of v
forest.link(s, t)
Links a pair of connected components together
s
and t
are both vertices(c) 2013-2014 Mikola Lysenko. MIT License