ds-algo-study/DS-n-Algos/Graphs/advanced/Graph.js

Just experimenting with publishing a package

// Graph
"use strict";

{
    class Graph {
        constructor () {
            this.nodes = new Set();
            this.edges = new Map();
        }
        addNode ( s ) {
            this.nodes.add( s );
        }
        addEdge ( s1, s2 ) {
            this.addNode( s1 );
            this.addNode( s2 );
            let s1Edges = this.edges.get( s1 );
            if ( !s1Edges ) {
                s1Edges = new Set();
                this.edges.set( s1, s1Edges );
            }
            s1Edges.add( s2 );
        }
        bfs ( node ) {
            if ( !node ) {
                node = [ ...this.nodes ][ 0 ];
            }
            const that = this;
            return {
                get [ Symbol.iterator ] () {
                    return () => iterative_bfs( that, node );
                }
            };
            function* iterative_bfs ( g, v ) {
                const q = [ v ];
                const marked = new Set();
                marked.add( v );
                while ( q.length ) {
                    const t = q.pop();
                    yield t;
                    const tEdges = that.edges.get( t );
                    for ( const adjacentNode of tEdges ) {
                        if ( !marked.has( adjacentNode ) ) {
                            marked.add( adjacentNode );
                            q.unshift( adjacentNode );
                        }
                    }
                }
            }
        }
    }

    Object.assign( self, { Graph } );

    test_graph();

    function test_graph () {
        const g = new Graph();
        g.addEdge( 'a', 'b' );
        g.addEdge( 'a', 'c' );
        g.addEdge( 'a', 'd' );
        g.addEdge( 'b', 'c' );
        g.addEdge( 'c', 'a' );
        g.addEdge( 'd', 'a' );
        Object.assign( self, { g } );
        console.log( g );
    }
}