https://github.com/nawatts/disjoint

Implementation of a disjoint set
https://github.com/nawatts/disjoint

data-structures disjoint-sets

Last synced: 5 days ago
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Implementation of a disjoint set

• Host: GitHub
• URL: https://github.com/nawatts/disjoint
• Owner: nawatts
• License: mit
• Created: 2016-07-30T20:11:37.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2022-12-30T21:01:17.000Z (about 2 years ago)
• Last Synced: 2024-12-02T04:44:00.559Z (about 1 month ago)
• Topics: data-structures, disjoint-sets
• Language: TypeScript
• Homepage: http://nawatts.github.io/disjoint
• Size: 816 KB
• Stars: 3
• Watchers: 2
• Forks: 2
• Open Issues: 12
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# disjoint

Implementation of a [disjoint set](https://en.wikipedia.org/wiki/Disjoint-set_data_structure).

Supports tracking arbitrary information about each subset and updating it as new links are added.

[![npm version](https://img.shields.io/npm/v/disjoint.svg)](https://www.npmjs.com/package/disjoint)

```JavaScript

// Example: 6 elements connected with weighted edges

// Edge weights are in parentheses

// Track maximum edge weight in each subset

//

//    0 -(2)- 1       2

//    |               |

//   (4)             (3)

//    |               |

//    3 -(1)- 4       5

//

const { DisjointSet } = require('disjoint');

const set = new DisjointSet(

  6, // Size of disjoint set

  function(s1, s2, edge) {

    // Reducer for updating subset properties when two subsets are joined.

    // s1: properties of one subset

    // s2: properties of the other subset

    // edge: edge properties, from third argument to union

    return {

      maxWeight: Math.max(s1.maxWeight, s2.maxWeight, edge.weight)

    }

  },

  { maxWeight: 0 } // Initial value for subset properties.

);

// Join elements

set.union(0, 1, { weight: 2 });

set.union(2, 5, { weight: 3 });

set.union(3, 4, { weight: 1 });

set.union(3, 0, { weight: 4 });

// Test if elements are connected

set.isConnected(0, 4); // true

set.isConnected(1, 2); // false

// Number of subsets

set.numSubsets(); // 2

// List of all subsets

set.subsets(); // [ [0, 1, 3, 4], [2, 5] ]

// Subset containing a specific element

set.subset(2) // [2, 5]

// Properties of subset containing a specific element

set.subsetProps(1) // { maxWeight: 4 }

```