Created
March 13, 2021 03:45
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class Graph { | |
constructor() { | |
this.vertices = []; | |
this.edges = []; | |
this.numberOfEdges = 0; | |
} | |
addVertex(vertex) { | |
this.vertices.push( vertex ); | |
this.edges[ vertex ] = []; | |
} | |
removeVertex(vertex) { | |
let index = this.vertices.indexOf( vertex ); | |
if ( ~index ) { | |
this.vertices.splice( index, 1 ); | |
} | |
while ( this.edges[ vertex ].length ) { | |
let adjacentVertex = this.edges[ vertex ].pop(); | |
this.removeEdge( adjacentVertex, vertex ); | |
} | |
} | |
addEdge(vertex1, vertex2) { | |
this.edges[ vertex1 ].push( vertex2 ); | |
this.edges[ vertex2 ].push( vertex1 ); | |
this.numberOfEdges++; | |
} | |
removeEdge(vertex1, vertex2) { | |
let index1 = this.edges[ vertex1 ] ? this.edges[ vertex1 ].indexOf( vertex2 ) : -1; | |
let index2 = this.edges[ vertex2 ] ? this.edges[ vertex2 ].indexOf( vertex1 ) : -1; | |
if ( ~index1 ) { | |
this.edges[ vertex1 ].splice( index1, 1 ); | |
this.numberOfEdges--; | |
} | |
if ( ~index2 ) { | |
this.edges[ vertex2 ].splice( index2, 1 ); | |
} | |
} | |
size() { | |
return this.vertices.length; | |
} | |
relations() { | |
return this.numberOfEdges; | |
} | |
traverseDFS(vertex, fn) { | |
if ( !~this.vertices.indexOf( vertex ) ) { | |
return console.log( 'Vertex not found' ); | |
} | |
let visited = []; | |
this._traverseDFS( vertex, visited, fn ); | |
} | |
_traverseDFS(vertex, visited, fn) { | |
visited[ vertex ] = true; | |
if ( this.edges[ vertex ] !== undefined ) { | |
fn( vertex ); | |
} | |
for ( let i = 0; i < this.edges[ vertex ].length; i++ ) { | |
if ( !visited[ this.edges[ vertex ][ i ] ] ) { | |
this._traverseDFS( this.edges[ vertex ][ i ], visited, fn ); | |
} | |
} | |
} | |
traverseBFS(vertex, fn) { | |
if ( !~this.vertices.indexOf( vertex ) ) { | |
return console.log( 'Vertex not found' ); | |
} | |
let queue = []; | |
queue.push( vertex ); | |
let visited = []; | |
visited[ vertex ] = true; | |
while ( queue.length ) { | |
vertex = queue.shift(); | |
fn( vertex ); | |
for ( let i = 0; i < this.edges[ vertex ].length; i++ ) { | |
if ( !visited[ this.edges[ vertex ][ i ] ] ) { | |
visited[ this.edges[ vertex ][ i ] ] = true; | |
queue.push( this.edges[ vertex ][ i ] ); | |
} | |
} | |
} | |
} | |
pathFromTo(vertexSource, vertexDestination) { | |
if ( !~this.vertices.indexOf( vertexSource ) ) { | |
return console.log( 'Vertex not found' ); | |
} | |
let queue = []; | |
queue.push( vertexSource ); | |
let visited = []; | |
visited[ vertexSource ] = true; | |
let paths = []; | |
while ( queue.length ) { | |
let vertex = queue.shift(); | |
for ( let i = 0; i < this.edges[ vertex ].length; i++ ) { | |
if ( !visited[ this.edges[ vertex ][ i ] ] ) { | |
visited[ this.edges[ vertex ][ i ] ] = true; | |
queue.push( this.edges[ vertex ][ i ] ); | |
// save paths between vertices | |
paths[ this.edges[ vertex ][ i ] ] = vertex; | |
} | |
} | |
} | |
if ( !visited[ vertexDestination ] ) { | |
return undefined; | |
} | |
let path = []; | |
for ( let j = vertexDestination; j != vertexSource; j = paths[ j ] ) { | |
path.push( j ); | |
} | |
path.push( j ); | |
return path.reverse().join( '-' ); | |
} | |
print() { | |
console.log( this.vertices.map( function ( vertex ) { | |
return ( vertex + ' -> ' + this.edges[ vertex ].join( ', ' ) ).trim(); | |
}, this ).join( ' | ' ) ); | |
} | |
} | |
let graph = new Graph(); | |
graph.addVertex( 1 ); | |
graph.addVertex( 2 ); | |
graph.addVertex( 3 ); | |
graph.addVertex( 4 ); | |
graph.addVertex( 5 ); | |
graph.addVertex( 6 ); | |
graph.print(); // 1 -> | 2 -> | 3 -> | 4 -> | 5 -> | 6 -> | |
graph.addEdge( 1, 2 ); | |
graph.addEdge( 1, 5 ); | |
graph.addEdge( 2, 3 ); | |
graph.addEdge( 2, 5 ); | |
graph.addEdge( 3, 4 ); | |
graph.addEdge( 4, 5 ); | |
graph.addEdge( 4, 6 ); | |
graph.print(); // 1 -> 2, 5 | 2 -> 1, 3, 5 | 3 -> 2, 4 | 4 -> 3, 5, 6 | 5 -> 1, 2, 4 | 6 -> 4 | |
console.log( 'graph size (number of vertices):', graph.size() ); // => 6 | |
console.log( 'graph relations (number of edges):', graph.relations() ); // => 7 | |
graph.traverseDFS( 1, vertex => { | |
console.log( vertex ); | |
} ); // => 1 2 3 4 5 6 | |
console.log( '---' ); | |
graph.traverseBFS( 1, vertex => { | |
console.log( vertex ); | |
} ); // => 1 2 5 3 4 6 | |
graph.traverseDFS( 0, vertex => { | |
console.log( vertex ); | |
} ); // => 'Vertex not found' | |
graph.traverseBFS( 0, vertex => { | |
console.log( vertex ); | |
} ); // => 'Vertex not found' | |
console.log( 'path from 6 to 1:', graph.pathFromTo( 6, 1 ) ); // => 6-4-5-1 | |
console.log( 'path from 3 to 5:', graph.pathFromTo( 3, 5 ) ); // => 3-2-5 | |
graph.removeEdge( 1, 2 ); | |
graph.removeEdge( 4, 5 ); | |
graph.removeEdge( 10, 11 ); | |
console.log( 'graph relations (number of edges):', graph.relations() ); // => 5 | |
console.log( 'path from 6 to 1:', graph.pathFromTo( 6, 1 ) ); // => 6-4-3-2-5-1 | |
graph.addEdge( 1, 2 ); | |
graph.addEdge( 4, 5 ); | |
console.log( 'graph relations (number of edges):', graph.relations() ); // => 7 | |
console.log( 'path from 6 to 1:', graph.pathFromTo( 6, 1 ) ); // => 6-4-5-1 | |
graph.removeVertex( 5 ); | |
console.log( 'graph size (number of vertices):', graph.size() ); // => 5 | |
console.log( 'graph relations (number of edges):', graph.relations() ); // => 4 | |
console.log( 'path from 6 to 1:', graph.pathFromTo( 6, 1 ) ); // => 6-4-3-2-1 |
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