union-find

A basic union-find data structure for node.js. For more information, see wikipdia:

Disjoint Set Datastructures

Usage

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');

//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);
}

Installation

npm install union-find

Acknowledgements

(c) 2013 Mikola Lysenko. MIT License