datastructures-js@datastructures-js/graph
Graph & Directed Graph implementation in javascript.
Contents
install
npm install --save @datastructures-js/graph
require
const { Graph, DirectedGraph } = require('@datastructures-js/graph');
import
import { Graph, DirectedGraph } from '@datastructures-js/graph';
API
constructor
Creates a new graph
JS
const directedGraph = new DirectedGraph();
const graph = new Graph();
TS
// DirectedGraph<T extends number|string, U = undefined>
const directedGraph = new DirectedGraph<number, { id: string, someProp: any }>();
// Graph<T extends number|string, U = undefined>
const graph = new Graph<string, number>();
addVertex
Adds a vertex to the graph.
directedGraph
.addVertex('v1', 1)
.addVertex('v2', 2)
.addVertex('v3', 3)
.addVertex('v4', 4)
.addVertex('v5', 5);
graph
.addVertex('v1', true)
.addVertex('v2', true)
.addVertex('v3', true)
.addVertex('v4', true)
.addVertex('v5', true);
hasVertex
Checks if the graph has a vertex by its key.
console.log(directedGraph.hasVertex('v7')); // false
console.log(graph.hasVertex('v1')); // true
getVertexValue
Returns the value associated with a vertex key.
console.log(directedGraph.getVertexValue('v5')); // 5
console.log(graph.getVertexValue('v1')); // true
getVerticesCount
Gets the number of vertices in the graph.
console.log(directedGraph.getVerticesCount()); // 5
console.log(graph.getVerticesCount()); // 5
addEdge
Adds a weighted edge between two existings vertices. Default weight is 1 if not defined. The single edge is a direction from source to destination in a directed graph, and a two-way connection in a graph.
directedGraph
.addEdge('v1', 'v2', 2)
.addEdge('v1', 'v3', 3)
.addEdge('v1', 'v4', 1)
.addEdge('v2', 'v4', 1)
.addEdge('v3', 'v5', 2)
.addEdge('v4', 'v3', 1)
.addEdge('v4', 'v5', 4);
graph
.addEdge('v1', 'v2', 2)
.addEdge('v2', 'v3', 3)
.addEdge('v1', 'v3', 6)
.addEdge('v2', 'v4', 1)
.addEdge('v4', 'v3', 1)
.addEdge('v4', 'v5', 4)
.addEdge('v3', 'v5', 2);
hasEdge
Checks if the graph has an edge between two existing vertices. In directed graph, it returns true only if there is a direction from source to destination.
console.log(directedGraph.hasEdge('v1', 'v2')); // true
console.log(directedGraph.hasEdge('v2', 'v1')); // false
console.log(graph.hasEdge('v1', 'v2')); // true
console.log(graph.hasEdge('v2', 'v1')); // true
getEdgesCount
Gets the number of edges in the graph.
console.log(directedGraph.getEdgesCount()); // 7
console.log(graph.getEdgesCount()); // 7
getWeight
Gets the edge's weight between two vertices. If there is no direct edge between the two vertices, it returns Infinity. It also returns 0 if the source key is equal to destination key.
console.log(directedGraph.getWeight('v1', 'v2')); // 2
console.log(directedGraph.getWeight('v2', 'v1')); // Infinity
console.log(directedGraph.getWeight('v1', 'v1')); // 0
console.log(graph.getWeight('v1', 'v2')); // 2
console.log(graph.getWeight('v2', 'v1')); // 2
console.log(graph.getWeight('v1', 'v1')); // 0
console.log(graph.getWeight('v1', 'v4')); // Infinity
getConnectedVertices
Returns a list of keys of vertices connected to a given vertex.
console.log(directedGraph.getConnectedVertices('v4')); // ['v3', 'v5']
console.log(graph.getConnectedVertices('v1')); // ['v2', 'v3']
getConnectedEdges
Returns an object of keys of vertices connected to a given vertex with the edges weight.
console.log(directedGraph.getConnectedEdges('v4')); // { v3: 1, v5: 4 }
console.log(graph.getConnectedEdges('v1')); // { v2: 2, v3: 6 }
removeVertex
Removes a vertex with all its edges from the graph.
directedGraph.removeVertex('v5');
console.log(directedGraph.getVerticesCount()); // 4
console.log(directedGraph.getEdgesCount()); // 5
graph.removeVertex('v5');
console.log(graph.getVerticesCount()); // 4
console.log(graph.getEdgesCount()); // 5
removeEdge
Removes an edge between two existing vertices
directedGraph.removeEdge('v1', 'v3'); // true
console.log(directedGraph.getEdgesCount()); // 4
graph.removeEdge('v2', 'v3'); // true
console.log(graph.getEdgesCount()); // 4
removeEdges
Removes all connected edges to a vertex and returns the number of removed edges.
const dg = new DirectedGraph()
.addVertex('v1')
.addVertex('v2')
.addVertex('v3')
.addEdge('v1', 'v2')
.addEdge('v2', 'v1')
.addEdge('v1', 'v3')
.removeEdges('v1'); // 3
const g = new Graph()
.addVertex('v1')
.addVertex('v2')
.addVertex('v3')
.addEdge('v1', 'v2')
.addEdge('v1', 'v3')
.removeEdges('v1'); // 2
traverseDfs
Traverses the graph from a starting vertex using the depth-first recursive search. it also accepts an optional third param as a callback to abort traversal when it returns true.
directedGraph.traverseDfs('v1', (key, value) => console.log(`${key}: ${value}`));
/*
v1: 1
v2: 2
v4: 4
v3: 3
*/
graph.traverseDfs('v1', (key, value) => console.log(`${key}: ${value}`));
/*
v1: true
v2: true
v4: true
v3: true
*/
let counter = 0;
graph.traverseDfs('v1', (key, value) => {
console.log(`${key}: ${value}`);
counter += 1;
}, () => counter > 1);
/*
v1: true
v2: true
*/
traverseBfs
Traverses the graph from a starting vertex using the breadth-first search with a queue. it also accepts an optional third param as a callback to abort traversal when it returns true.
directedGraph.traverseBfs('v1', (key, value) => console.log(`${key}: ${value}`));
/*
v1: 1
v2: 2
v4: 4
v3: 3
*/
graph.traverseBfs('v1', (key, value) => console.log(`${key}: ${value}`));
/*
v1: true
v2: true
v3: true
v4: true
*/
let counter = 0;
graph.traverseBfs('v1', (key, value) => {
console.log(`${key}: ${value}`);
counter += 1;
}, () => counter > 1);
/*
v1: true
v2: true
*/
clear
Clears all vertices and edges in the graph.
directedGraph.clear();
console.log(directedGraph.getVerticesCount()); // 0
console.log(directedGraph.getEdgesCount()); // 0
graph.clear();
console.log(graph.getVerticesCount()); // 0
console.log(graph.getEdgesCount()); // 0
Build
grunt build
License
The MIT License. Full License is here